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Davis recanted the next day. At trial, Logemann also recalled
a conversation he had with Davis several days after the mur-
ders about the possibility of a gun being left at the scene.
Logemann testified that Davis was concerned that through
DNA evidence, investigators would be able to link the gun
to Davis as the shooter. The .40-caliber semiautomatic pistol
abandoned at the site of the murders was consistent with bul-
lets recovered from the scene.
   The prosecution presented a significant amount of evidence
to establish Davis’ involvement at every step, from the plan-
ning stage of the robbery to the actual robbery attempt and
murders, to disposing of one of the murder weapons, and to
Davis’ incriminating statements after the murders occurred.
The evidence was sufficient such that a rational trier of fact,
viewing the evidence in a light most favorable to the prosecu-
tion, could find that Davis was guilty of all charges beyond a
reasonable doubt.
   Davis’ second assignment of error is without merit.
                     VI. CONCLUSION
   We affirm Davis’ convictions and sentences.
                                                                         Affirmed.



       Elizabeth Grant Johnson, now known as Elizabeth
        D’Allura, appellant and cross-appellee, v. Kari
             Johnson, appellee and cross-appellant.
                                    ___ N.W.2d ___

                         Filed May 15, 2015.     No. S-13-775.

 1.	 Modification of Decree: Child Support: Appeal and Error. Modification of a
     dissolution decree is a matter entrusted to the discretion of the trial court, whose
     order is reviewed de novo on the record, and which will be affirmed absent an
     abuse of discretion by the trial court. The same standard applies to the modifica-
     tion of child support.
 2.	 Judgments: Appeal and Error. When reviewing questions of law, an appellate
     court has an obligation to resolve the questions independently of the conclusion
     reached by the court below.
 3.	 Rules of the Supreme Court: Child Support. In general, child support pay-
     ments should be set according to the Nebraska Child Support Guidelines.
                         Nebraska Advance Sheets
	                              JOHNSON v. JOHNSON	839
	                                Cite as 290 Neb. 838

 4.	 Child Support. Use of earning capacity to calculate child support is useful when
     it appears that the parent is capable of earning more income than is presently
     being earned.
 5.	 Child Support: Evidence. Generally, earning capacity should be used to deter-
     mine a child support obligation only when there is evidence that the parent can
     realize that capacity through reasonable efforts.
 6.	 Social Security. Social Security benefits are not a mere gratuity from the federal
     government but have been earned through an employee’s payment of Social
     Security taxes.
 7.	 Child Support: Appeal and Error. Whether a child support order should be
     retroactive is entrusted to the discretion of the trial court, and an appellate court
     will affirm its decision absent an abuse of discretion.
 8.	 Modification of Decree: Child Support. In determining whether to order a ret-
     roactive modification of child support, a court must consider the parties’ status,
     character, situation, and attendant circumstances.
 9.	 Modification of Decree: Child Support: Time. Absent equities to the contrary,
     modification of a child support order should be applied retroactively to the first
     day of the month following the filing date of the application for modification.
10.	 Modification of Decree: Child Support. In modification of child support pro-
     ceedings, the children and the custodial parent should not be penalized by delay
     in the legal process, nor should the noncustodial parent gratuitously benefit from
     such delay.
11.	 Child Support. The general rule is that no credit is given for voluntary overpay-
     ments of child support, even if they are made under a mistaken belief that they
     are legally required.

   Petition for further review from the Court of Appeals,
Moore, Chief Judge, and Irwin and Pirtle, Judges, on appeal
thereto from the District Court for Douglas County, Shelly R.
Stratman, Judge. Judgment of Court of Appeals affirmed in
part and in part reversed, and cause remanded with directions.
  Rodney C. Dahlquist, Jr., and Christine A. Lustgarten, of
Dornan, Lustgarten & Troia, P.C., L.L.O., for appellant.
  Virginia A. Albers, of Slowiaczek, Albers & Astley, P.C.,
L.L.O., for appellee.
  Heavican, C.J., Wright, Connolly, Stephan, McCormack,
Miller-Lerman, and Cassel, JJ.
  Miller-Lerman, J.
                  I. NATURE OF CASE
  Kari Johnson filed a petition for further review of the
Nebraska Court of Appeals’ decision which affirmed in part
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and reversed in part the order of the district court for Douglas
County which modified his child support obligation. We con-
clude that (1) the Court of Appeals correctly determined that
the district court erred when it imputed to Elizabeth Grant
Johnson, now known as Elizabeth D’Allura, a wage-earning
capacity of $52,000 per year and reversed the order and
remanded the cause for a hearing on Elizabeth’s wage-earning
capacity, (2) the Court of Appeals did not err when it affirmed
the district court’s conclusion that the Social Security benefits
paid to the children were a gratuity and that Kari should not
be given a credit for them upon remand, and (3) although
the Court of Appeals correctly affirmed the district court’s
decisions that a downward modification in Kari’s child sup-
port could be retroactive to the month after the filing of the
application to modify, that the judgment against Elizabeth for
$25,472.11 should be reversed, and that a judgment against
Elizabeth for $2,357.90 should be entered, it erred when it
reasoned that upon remand, Kari could not receive credit
for overpayments, if any, made during the pendency of the
modification proceedings for the reason that Kari had contin-
ued to pay the $3,000-per-month child support ordered in the
original decree. To the contrary, the fact that Kari continued
to pay what had been ordered does not preclude consideration
of a potential credit after receipt of additional evidence upon
remand. Accordingly, we affirm in part, and in part reverse and
remand with directions.

                 II. STATEMENT OF FACTS
   Kari and Elizabeth were married in 1996. Two children were
born to the marriage: one born in May 1995 and one born in
July 1998. Kari and Elizabeth were divorced in January 2010,
when the district court entered a stipulated decree and parent-
ing plan. The dissolution decree, inter alia, provided for joint
legal custody of the children and awarded physical custody to
Elizabeth. Per the stipulation, the decree required Kari to pay
child support of $3,000 per month while both children were
minors and $1,500 per month when only the younger child was
a minor.
                  Nebraska Advance Sheets
	                     JOHNSON v. JOHNSON	841
	                       Cite as 290 Neb. 838

   Approximately 6 months after entry of the decree of dis-
solution, Kari moved for an order nunc pro tunc, in which
motion he asserted that the dissolution court was not aware
of the Social Security payments the children were receiving
and that had the dissolution court been aware of the Social
Security benefits, Kari “would be responsible for far less than
the $3,000” monthly amount of child support. Kari later with-
drew the motion, and thus the dissolution court never enter-
tained it.
   At the January 2013 modification trial which gives rise
to this appeal, Kari acknowledged that when he stipulated
to the terms of the original decree, filed on January 10,
2010, he understood that the children were receiving Social
Security benefits by virtue of his status as a retired taxpayer.
He acknowledged that the receipt of the Social Security ben-
efits was in addition to his obligations for child support and
alimony. The record shows that the children received Social
Security benefits in 2010, 2011, and part of 2012.
   Nine months after the decree of dissolution was entered,
Kari moved to vacate the decree, asserting that the decree was
void because the district court lacked personal jurisdiction over
him. We affirmed the district court’s order denying the motion
to vacate the decree of dissolution. Johnson v. Johnson, 282
Neb. 42, 803 N.W.2d 420 (2011). At the modification trial,
Kari testified that he pursued the personal jurisdiction issue
rather than first applying for a modification, because he wanted
a “do-over” and to have the entire decree overturned.
   In September 2011, Kari filed an application to modify the
decree, in which he sought to be awarded physical custody
based on the children’s preference and to have child support
recalculated accordingly. Elizabeth filed a cross-application
in which she sought sole legal custody based on Kari’s unco-
operative behavior and his failure to pay his share of medi-
cal bills and to maintain his life insurance. Kari thereafter
amended his application to allege that in the event physical
custody remained with Elizabeth, his child support obligation
should be modified downward because he had experienced
a decrease in income which constituted a material change in
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circumstances. The parties ultimately stipulated to a modifica-
tion of physical custody to a joint physical (as well as legal)
custody arrangement.
   In January 2013, trial was eventually held on the issue of
appropriate modification of child support. A review of the
supplemental transcript shows that during the pendency of
Kari’s motion to modify which had been filed in September
2011, a trial was set for April 10, 2012; the parties “settled” the
matter, but after the trial date had passed, Elizabeth repudiated
the settlement. On September 6, Kari sought temporary abate-
ment of child support. And on October 19, 2012, Kari filed an
additional motion for temporary adjustment of child support
and a motion for credit. Elizabeth successfully sought continu-
ance of Kari’s temporary motions to adjust or credit child sup-
port. Specifically, the district court ordered that Kari’s motions
for abatement or credit of child support were to be addressed
at trial. The trial was set for January 2013. The judge who
heard the modification matter was not the judge who entered
the decree.
   At the time of trial, Kari was 69 years old and Elizabeth
was 47 years old. Both parties testified that Elizabeth had
remained in the family home because they wanted to maintain
stability for the children. The record reflects that at the time
of trial, Elizabeth’s only income was payments she received
from a blind trust. She testified that she generally received
about $27,000 to $28,000 per year from the trust, or approxi-
mately $2,300 per month. Her monthly expenses at the time
of the modification trial for the mortgage, utilities, and food
totaled more than $4,000, but she admitted that her food
expenses would be reduced by the joint custody arrangement.
Elizabeth testified that she did not have any money. In its rul-
ing on the modification, the district court found that the evi-
dence showed that Elizabeth received a $95,000 inheritance
during the marriage, the equity in the $500,000 marital home
in the divorce, and an unexplained deviation upward in child
support, and that her new husband contributed to the family’s
home expenses.
   Elizabeth had previously been employed by an aircraft
charter company as a pilot; in 2004, she was employed full
                   Nebraska Advance Sheets
	                      JOHNSON v. JOHNSON	843
	                        Cite as 290 Neb. 838

time and earned $23,000. There was evidence that Elizabeth
would be eligible for a copilot position with her former
employer at a salary of $1,500 per month, or $18,000 per year.
However, to accept the position, she would have to move from
Omaha, Nebraska, to California and undergo a minimum of 4
weeks’ requalification training, which training Elizabeth testi-
fied would cost $10,000 and would be deducted from her pay.
Elizabeth testified that there were no jobs available for her as a
pilot in the Omaha area. Elizabeth further testified that she had
an ongoing medical condition which prevented her from attain-
ing the medical clearance necessary to work as a commercial
pilot. Neither party elicited an explanation of Elizabeth’s medi-
cal condition.
   At the time of trial, Kari was employed as a director of
safety at a charter management company for aircraft. Kari testi-
fied that he had been involved in the aviation industry for 50
years. Kari testified that while he “may not be an expert wit-
ness,” in his opinion, Elizabeth could earn “anywhere from 60
to 80,000 a year” as a licensed pilot. Kari testified that he could
provide “lots of names” of companies paying in the $60,000
to $80,000 range, “but they’re supposed to be confidential.”
Kari testified that Elizabeth could earn $52,000 per year at her
former workplace, though he had “no idea” whether she had
achieved such earnings there previously. He requested that the
district court impute a wage-earning capacity of $52,000 per
year to Elizabeth.
   The parties submitted their respective proposed support cal-
culations. Kari proposed that his child support obligation,
based on joint physical custody, be reduced to $1,692 per
month, retroactive to October 2011 (the month after he filed for
modification), and that after the date of the modification order,
his obligation be set at $450 per month for two children. He
requested a “credit” of more than $19,000 which would reflect
the difference between the $3,000 per month he had paid for
child support since October 2011 (during the pendency of the
modification) and the new amount he proposed as his obliga-
tion during that time. He also requested a credit for almost
$63,000 for Social Security benefits received by the children
but never credited against his support obligation.
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   Elizabeth testified that she inadvertently removed $2,357.90
from an account of Kari’s to pay her American Express bill.
Kari requested a judgment to reimburse him for that amount.
   Elizabeth proposed that Kari’s child support obligation,
based on joint physical custody, be set at $1,095 per month.
She testified that adjusting the support obligation to give Kari
a credit for past Social Security benefits paid to the children
would present a significant hardship for her and the children.
Elizabeth’s counsel also informed the district court that Kari
had previously filed a motion seeking to address the Social
Security benefits but had withdrawn it. Elizabeth’s counsel
argued that to allow a retroactive credit after the accumulation
of such benefits for more than 3 years since the decree had
been entered would be inequitable.
   The ensuing orders are complicated and summarized here. In
summary, the district court entered an order in May 2013; then
later in May, entered a nunc pro tunc order clarifying certain
issues; and on August 16, filed an order ruling on Kari’s motion
to alter or amend in which the district court amended aspects
of its prior order. The August order is the order appealed from,
but earlier orders found facts relevant to our consideration
on further review. For purposes of the issues relevant to this
appeal concerning child support, the district court ultimately
made rulings as follows:
   Reasonable expenditures for the children, such as clothing
and extracurricular activities, were allocated between the par-
ents, commencing October 1, 2011, such that Elizabeth would
be responsible for 40 percent and Kari would be responsible
for 60 percent.
   The district court applied the Nebraska Child Support
Guidelines, and in connection with its calculation of Kari’s
child support obligations, the district court used Kari’s earn-
ings at the time of the modification trial, which were less than
his earnings at the time of the divorce, to calculate his monthly
income. The district court found Kari’s testimony concerning
Elizabeth’s earning capacity to be credible and reasonable,
based on his experience as a pilot and his knowledge of the
aviation industry, and determined that Elizabeth had a wage-
earning capacity of $52,000 per year, even though she was
                   Nebraska Advance Sheets
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	                        Cite as 290 Neb. 838

not employed at the time of trial. The district court calculated
Elizabeth’s monthly income based on the $52,000 potential
wage earnings as well as the approximately $27,000 per year
that she received as payments from a blind trust. The district
court did not find Elizabeth’s testimony to the effect that she
was unable to work due to an unspecified medical condition to
be credible.
   In determining Kari’s child support obligation, the district
court noted that Kari’s child support obligation from January
2010, when the divorce decree was entered, through September
2011, when he filed his application to modify the decree, was
$3,000 per month as set forth in the stipulated decree. The
district court determined that Kari’s child support obligation
should be reduced to $1,658 per month from October 2011, the
month following the month in which he applied to modify the
decree, through December 2012. In January 2013, the parties
began joint physical custody. The district court determined that
Kari’s child support obligation should be set at $443 per month
from January 2013 through May 2014, a period during which
both children would be minors, and $311 per month from June
2014 until July 2017, a period during which only one child
would be a minor.
   In its several orders, the district court reasoned that because
Kari had paid an upward adjustment of $3,000 per month
during the pendency of the modification proceedings but his
obligation was reduced retroactive to October 2011, Kari had
in effect overpaid child support. Specifically, in view of the
fact that, applying the child support guidelines, it had deter-
mined that Kari’s child support payment should be reduced
from $3,000 per month to $1,658 per month from October
2011 to December 2012, $443 from January 2013 to May
2014, and $311 from June 2014 to July 2017, and its order was
not filed until August 16, 2013, the district court determined
that Kari was entitled to a credit of $41,852.11 as a result
of his “overpayment” of child support obligations during the
pendency of the modification proceedings. The district court
awarded Kari a credit of $16,380 against his future child sup-
port obligations and, because the overpayment credit would
not be wholly consumed, a judgment against Elizabeth for the
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remaining $25,472.11. This judgment included the $2,357.90
that Elizabeth had withdrawn from an account of Kari’s to pay
her American Express bill, but this portion of the judgment is
not disputed on appeal.
   With respect to the payment of Social Security benefits to
the children, the district court concluded that under Nebraska
jurisprudence, it could not equitably provide Kari a credit for
the Social Security benefits received by the children. The dis-
trict court reasoned that if such benefits had been disclosed
at the time of the decree of dissolution, it could have reduced
Kari’s child support obligation by effectively attributing such
payments to Kari’s child support obligation, but because the
parties had stipulated to a child support obligation of $3,000
per month in the stipulated decree, the district court had to treat
the Social Security benefits as a gratuitous overpayment.
   Elizabeth appealed the district court’s order to the Court
of Appeals, and Kari cross-appealed. In her appeal, Elizabeth
claimed, inter alia, that the district court erred when it (1)
determined the parties’ earning capacities and (2) granted Kari
a credit against future child support obligations for past over-
payments of child support during the pendency of these modi-
fication proceedings and granted Kari a judgment against her
for the balance of the credit which exceeded future child sup-
port obligations. Elizabeth made another assignment of error
regarding retroactivity of the modification, which assignment
of error the Court of Appeals rejected. Elizabeth did not cross-
petition for further review of this issue. In his cross-appeal,
Kari claimed only that the district court erred when it refused
to award him a credit against his child support obligations for
the Social Security benefits that had been paid to the children
based on his work history.
   The Court of Appeals affirmed the district court’s orders in
part, reversed the orders in part, and remanded the cause for
further proceedings in a memorandum opinion filed October 1,
2014, in case No. A-13-775. The Court of Appeals determined
that the district court abused its discretion when it imputed a
wage-earning capacity of $52,000 per year to Elizabeth. The
Court of Appeals determined that there was not sufficient
evidence demonstrating that she could realize such a level
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	                     JOHNSON v. JOHNSON	847
	                       Cite as 290 Neb. 838

of earnings and remanded the cause for the determination
of “an appropriate level of earning capacity [for Elizabeth]
that is supported by competent evidence in the record.” The
Court of Appeals also determined that although the district
court’s determination that Kari should get relief retroactively
was not error, because Kari continued to pay the $3,000 per
month child support required in the decree, the district court
erred when it granted Kari a credit against future child sup-
port obligations and further erred when it entered a judgment
against Elizabeth for the anticipated unused overpayment of
child support. Finally, the Court of Appeals rejected Kari’s
assignment of error on cross-appeal and concluded that the
district court did not err when it had concluded that the
Social Security benefits received by the children were a gra-
tuitous payment that could not be credited against Kari’s child
support obligations. We summarize the Court of Appeals’
memorandum opinion in more detail in the analysis portion
of this opinion.
   Kari petitioned for further review of the Court of Appeals’
memorandum opinion. We granted the petition.

                III. ASSIGNMENTS OF ERROR
   Kari claims the Court of Appeals erred when it determined
that (1) the district court erred when it imputed to Elizabeth
a wage-earning capacity of $52,000 per year, (2) the district
court correctly determined that Kari should not be given credit
against his child support obligation for Social Security benefits
paid to the children, and (3) the district court erred when it
gave Kari credit for overpayment of child support obligations
in the form of a credit against future child support obligations
and in the form of a judgment against Elizabeth.

                IV. STANDARDS OF REVIEW
   [1] Modification of a dissolution decree is a matter entrusted
to the discretion of the trial court, whose order is reviewed
de novo on the record, and which will be affirmed absent an
abuse of discretion by the trial court. Garza v. Garza, 288 Neb.
213, 846 N.W.2d 626 (2014). The same standard applies to the
modification of child support. Id.
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   [2] When reviewing questions of law, an appellate court has
an obligation to resolve the questions independently of the con-
clusion reached by the court below. See Jensen v. Jensen, 275
Neb. 921, 750 N.W.2d 335 (2008).
                           V. ANALYSIS
             1. Elizabeth’s Wage-Earning Capacity
   Kari claims that the Court of Appeals erred when it
reversed the portion of the district court’s order imputing a
wage-­earning capacity of $52,000 per year to Elizabeth and
remanded the cause for a determination of Elizabeth’s earning
capacity. We reject this assignment of error.
   [3-5] We have previously addressed the law applicable to
determining a parent’s earning capacity for child support pur-
poses and stated:
         In general, child support payments should be set accord-
      ing to the Nebraska Child Support Guidelines. The guide-
      lines provide that “[i]f applicable, earning capacity may
      be considered in lieu of a parent’s actual, present income
      and may include factors such as work history, education,
      occupational skills, and job opportunities. Earning capac-
      ity is not limited to wage-earning capacity, but includes
      moneys available from all sources.” Use of earning capac-
      ity to calculate child support is useful “when it appears
      that the parent is capable of earning more income than is
      presently being earned.”
Freeman v. Groskopf, 286 Neb. 713, 720, 838 N.W.2d 300,
307 (2013). Generally, earning capacity should be used to
determine a child support obligation only when there is evi-
dence that the parent can realize that capacity through reason-
able efforts. See Johnson v. Johnson, 20 Neb. App. 895, 834
N.W.2d 812 (2013).
   The record shows that at the time of trial, Elizabeth’s actual
income was about $27,000 to $28,000 per year from a trust.
The record indicates that the trust income was expected to con-
tinue. Therefore, the issue with regard to her earning capacity
focuses on her ability for wage earning.
   At the time of trial, Kari worked as a director of safety at a
charter management company for aircraft. Based on his nearly
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50 years in the aviation industry, Kari opined that Elizabeth
could earn $60,000 to $80,000 per year as a licensed pilot.
Kari testified that while he knew “lots of names” of compa-
nies paying in that range, those names were “supposed to be
confidential.” Kari requested that the district court impute to
Elizabeth an annual earning capacity of $52,000, which he
testified she could earn at her former workplace, though he
had “no idea” whether she had achieved such earnings there in
the past. The district court found Kari’s testimony concerning
Elizabeth’s wage-earning capacity to be credible and reason-
able based on his years of experience in the aviation industry
and determined that Elizabeth had a wage-earning capacity of
$52,000 per year.
   The trial record shows that Elizabeth’s wage earnings had
peaked at $23,000 in 2004, when she was employed as a full-
time pilot. Elizabeth testified that there were no jobs avail-
able for her as a pilot in the Omaha area at the time of trial.
There was evidence that she was eligible for a pilot position
with a former employer at a salary of $18,000 per year, but
that accepting the position would require her to relocate to
California and pay $10,000 for training. Elizabeth stated
that a medical condition prevented her from working as a
commercial pilot. The district court did not find Elizabeth’s
testimony concerning her unspecified medical condition to
be credible.
   With regard to Elizabeth’s wage-earning capacity, the Court
of Appeals determined that the record supported imputing
some level of earning capacity to Elizabeth, but that the only
evidence setting that figure at $52,000 annually was Kari’s
unsupported testimony of his opinion of Elizabeth’s poten-
tial earnings in the aviation field. There was conflicting evi-
dence regarding Elizabeth’s ability to work as a pilot, and as
it was permitted to do, the Court of Appeals gave weight to
the fact that the trial judge heard and observed the witnesses
and rejected Elizabeth’s version in which she testified that an
unspecified medical condition rendered her unable to work as
a pilot. See Brockman v. Brockman, 264 Neb. 106, 646 N.W.2d
594 (2002). Thus, the Court of Appeals accepted the district
court’s conclusion that Elizabeth was able to work, but it
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determined that the district court abused its discretion when it
imputed an annual wage-earning capacity of $52,000 based on
the record and remanded the cause for further evidence on this
issue. Following our de novo review of the evidence, we find
no error by the Court of Appeals in this regard.
   A review of the record shows that although Kari was
employed in the aviation industry in some capacity for many
years, he did not testify that he had a specific basis for his pur-
ported knowledge of compensation for pilots or positions avail-
able for pilots. He did not refer to any research or inquiries on
the matter, demonstrated limited knowledge of Elizabeth’s past
earnings, declined to specify names of potential employers, and
admitted that he “may not be an expert witness.” Further, as
the Court of Appeals pointed out, the evidence of Elizabeth’s
full-time job offer with her former employer for $18,000 per
year called into question Kari’s opinion that she could obtain
employment there at a rate of $52,000 per year, as well as
his contention that she is capable of earning that sum. On the
record before us, it appears that with relocation and training
requirements, attaining the position with Elizabeth’s former
employer could require her to exert something more than “rea-
sonable efforts.”
   Following our de novo review of the record, we agree with
the Court of Appeals that the evidence does not support the
district court’s determination Elizabeth had an annual wage-
earning capacity of $52,000 and that in so finding, the district
court abused its discretion. Because determination of the par-
ties’ income or earning capacity is critical to the determination
of child support, this portion of the order must be reversed and
the cause remanded for a determination of Elizabeth’s wage-
earning capacity. Accordingly, we affirm the Court of Appeals’
ruling reversing the matter of Elizabeth’s earning capacity and
remand the cause to the district court.
   Kari raises several issues in addition to Elizabeth’s earning
capacity in his petition for further review. Although the resolu-
tion of these issues is not entirely necessary to the disposition
of the current appeal, we address them below because they
are relevant to the complete disposition of the matter upon
remand. See In re Interest of Laurance S., 274 Neb. 620, 742
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N.W.2d 484 (2007) (appellate court may, at its discretion, dis-
cuss issues unnecessary to disposition of appeal where those
issues are likely to recur during further proceedings).

                  2. Social Security Benefits
                        Paid to Children
   Kari claims that the Court of Appeals erred when it affirmed
the district court’s determination that Kari should not be
given credit against his child support obligation for the Social
Security benefits which were paid to the children. He contends
that these benefits should not have been treated as gratuitous
payments to the children. Kari asserts that he was entitled
to have his child support obligation offset by the amount of
Social Security benefits the children have received. We find
no merit to this assignment of error and therefore affirm the
decision of the Court of Appeals which affirmed the ruling of
the district court which deemed the Social Security benefits
a gratuity.
   [6] We have considered the issue of applying Social Security
benefits to meet a parent’s child support obligation on several
occasions. E.g., Gress v. Gress, 257 Neb. 112, 596 N.W.2d
8 (1999); Hanthorn v. Hanthorn, 236 Neb. 225, 460 N.W.2d
650 (1990); Lainson v. Lainson, 219 Neb. 170, 362 N.W.2d
53 (1985); Schulze v. Jensen, 191 Neb. 253, 214 N.W.2d 591
(1974). The cases often involve disability benefits or child
support arrearages, but we find guidance in their reasoning.
We have explained that Social Security benefits are not a mere
gratuity from the federal government but have been earned
through an employee’s payment of Social Security taxes. See
Brewer v. Brewer, 244 Neb. 731, 509 N.W.2d 10 (1993). A
request to apply Social Security benefits to a child support
obligation is merely a request to identify the source of pay-
ment. See Gress v. Gress, supra. A Social Security benefit can
serve as a substitute source for income. See id.
   Cases illustrate that the better practice is to make the dis-
solution court cognizant of the payment of Social Security
benefits to the children at the time of entering the decree so
that the dissolution court can make a fully informed decision.
See Hanthorn v. Hanthorn, supra (discussing collected cases).
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It nevertheless remains at the court’s discretion, depending on
the overall situation of both the parties and children, to order
child support in addition to the amounts received from Social
Security. E.g., Lainson v. Lainson, supra.
   With respect to the Social Security payments under the facts
of this case, the district court determined that under Nebraska
jurisprudence, it could not equitably provide Kari a credit
for the Social Security benefits received by the children. The
district court reasoned that if the Social Security benefits had
been disclosed at the time of the divorce proceedings, the dis-
solution court could have attributed such payments to Kari’s
child support obligation. However, because the parties did not
inform the dissolution court of the Social Security payments
at the time of the divorce and had agreed to a child support
obligation of $3,000 per month in the stipulated decree with
no explanation of the upward deviation, the district court
determined that it was obligated to treat the Social Security
benefits as a gratuitous payment. On appeal, the Court of
Appeals agreed.
   Based on the jurisprudence set forth above, the procedural
history, and the equities of the case, we conclude that the Court
of Appeals correctly affirmed the district court’s determination
and we affirm the Court of Appeals’ decision on this issue. The
record shows that the children received Social Security benefits
in 2010, 2011, and part of 2012. Kari testified that when he
stipulated to the terms of the original decree, entered January
10, 2010, he understood that the children were receiving Social
Security benefits by virtue of his status as a retired taxpayer
and that these benefits were in addition to his obligations for
child support and alimony.
   Approximately 6 months after entry of the decree of dis-
solution, Kari filed a motion for an order nunc pro tunc, in
which motion he asserted that the dissolution court was not
aware of the fact the children were receiving Social Security
payments and that had the dissolution court been aware of
such fact, Kari’s child support amount would have been “far
less.” Kari later chose to withdraw the motion, and the dis-
solution court did not address it. Rather than applying early
on for a modification of the child support order to reflect
                  Nebraska Advance Sheets
	                     JOHNSON v. JOHNSON	853
	                       Cite as 290 Neb. 838

receipt of Social Security benefits as the partial source of his
obligation, Kari decided to pursue the personal jurisdiction
issue—which we rejected in Johnson v. Johnson, 282 Neb.
42, 803 N.W.2d 420 (2011)—because he wanted a “do-over.”
Thus, Kari knowingly waived an early opportunity to address
the Social Security issue and chose instead “to gamble on the
ultimate outcome” of his first appeal. Hanthorn v. Hanthorn,
236 Neb. 225, 231, 460 N.W.2d 650, 654 (1990).
   In light of our jurisprudence and the equities of the case, we
conclude that the Court of Appeals did not err when it affirmed
the district court’s determination that the Social Security pay-
ments made to the children should be treated as a gratuity.
Accordingly, Kari should receive no child support credit for the
Social Security payments upon remand.

            3. Child Support Credit and Judgment
   Kari claims the Court of Appeals erred when it reversed the
district court’s decision which found that Kari had overpaid
child support during the pendency of the modification pro-
ceedings, granted Kari a credit for overpayment against future
child support, and entered a judgment against Elizabeth for the
anticipated unused overpayment. Because of our remand for
a determination of Elizabeth’s earning capacity, we address
Kari’s assignment of error for guidance on remand.

                  (a) Retroactive Modification
                        of Child Support
   [7] We begin by addressing whether a retroactive modifi-
cation of Kari’s child support is permissible under the facts
of this case. Both the district court and the Court of Appeals
determined that if Kari was found to have overpaid during the
pendency of the modification proceedings and it was deter-
mined that he was entitled to a credit, the credit could be
applied retroactively to the month after Kari filed for modi-
fication. Whether a child support order should be retroactive
is entrusted to the discretion of the trial court, and we will
affirm its decision absent an abuse of discretion. Freeman v.
Groskopf, 286 Neb. 713, 838 N.W.2d 300 (2013). Applying
the law to the facts of this case, we agree that retroactive
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modification is appropriate if the further evidence shows an
overpayment and the principles applicable to awarding a credit
are met.
   [8-10] In determining whether to order a retroactive modi-
fication of child support, a court must consider the parties’
status, character, situation, and attendant circumstances. See,
Wilkins v. Wilkins, 269 Neb. 937, 697 N.W.2d 280 (2005);
Cooper v. Cooper, 8 Neb. App. 532, 598 N.W.2d 474 (1999).
Absent equities to the contrary, modification of a child support
order should be applied retroactively to the first day of the
month following the filing date of the application for modifi-
cation. See Freeman v. Groskopf, supra. The children and the
custodial parent should not be penalized by delay in the legal
process, nor should the noncustodial parent gratuitously benefit
from such delay. Pursley v. Pursley, 261 Neb. 478, 623 N.W.2d
651 (2001); McDonald v. McDonald, 21 Neb. App. 535, 840
N.W.2d 573 (2013).
   In ruling on Kari’s motion for modification, the district
court based its child support calculation on its finding that
Elizabeth had a wage-earning capacity of $52,000 per year
and reasoned that Kari had overpaid his child support obliga-
tion when he paid $3,000 per month during the pendency of
the modification proceedings. Kari had filed his application
for modification in September 2011, and the district court ret-
roactively reduced Kari’s child support obligation by varying
amounts from October 2011 to the time of the modification
ruling and forward to July 2017. The district court ordered
that Kari be compensated for his overpayment by receiv-
ing credit against his future child support obligations and
by receiving a lump-sum judgment against Elizabeth for the
unused overpayment. Although the Court of Appeals deter-
mined that the district court’s conclusion approving retroac-
tive modification was not an abuse of discretion, the Court of
Appeals ultimately concluded that because Kari had agreed
to pay $3,000 per month in the decree, he was not eligible to
receive a credit.
   Regarding the retroactive issue, on our de novo review of
the record, we find no equities that would support a decision
not to apply a modified child support obligation of Kari’s
                  Nebraska Advance Sheets
	                     JOHNSON v. JOHNSON	855
	                       Cite as 290 Neb. 838

retroactively to October 2011, the month following the filing
of Kari’s motion to modify. Although Elizabeth’s wage-earning
capacity is yet to be determined, it is undisputed that she will
continue to receive income of approximately $27,000 per year
from the trust; that she now shares joint physical custody with
Kari, resulting in some reduction of expenses; and that the chil-
dren have retained the Social Security benefits, which at trial
were approximately $63,000.
    We also observe that the legal process for resolving Kari’s
modification effort has contributed to delay, and in equity, he
should not be penalized therefor. We have stated that in the
context of retroactive modification, parties ought not be penal-
ized by delay in the legal process, nor should a party gratu-
itously benefit from such delay. See Pursley v. Pursley, supra.
The judge who presided over the dissolution was not the judge
who presided over the modification, and it has been suggested
that some delay in the disposition of this matter was due, in
part, to the retirement of the first judge and the ensuing reas-
signment of the case.
    Accordingly, we conclude that retroactive modification of
Kari’s child support obligation and the timing of retroactive
modification from the first day of the month following the
filing of the application for modification are permissible in
this case.

             (b) Credit for Modified Child Support
   As noted above, the district court partly based its child sup-
port calculation on its erroneous finding that Elizabeth had an
annual wage-earning capacity of $52,000. The district court
applied the child support guidelines and found that Kari was
entitled to a reduced child support obligation and that he had
overpaid his child support obligation by paying $3,000 per
month while the modification proceedings were pending. The
court ordered that Kari be compensated for his overpayment,
in part by a credit against his future child support obligations
and in part by a lump-sum judgment against Elizabeth. On
appeal, the Court of Appeals essentially determined that Kari
could not have overpaid child support, because he had stipu-
lated to the $3,000-per-month child support payment in the
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decree, and that therefore, Kari was not eligible for a credit.
We disagree with the reasoning of the Court of Appeals. Upon
remand, after receipt of evidence of Elizabeth’s wage-earning
capacity and application of the child support guidelines, if it
appears that Kari has overpaid child support during the pend­
ency of the modification proceedings, on the facts of this
record, Kari is not ineligible for a credit by virtue of having
paid the $3,000 per month. Whether Kari is awarded a credit
under the exception in Griess v. Griess, 9 Neb. App. 105, 608
N.W.2d 217 (2000), explained below, is to be determined by
the district court upon remand.
   [11] The Court of Appeals has enunciated the general rule
for support overpayment claims: No credit is given for vol-
untary overpayments of child support, even if they are made
under a mistaken belief that they are legally required. See id.
However, the general rule continues that “[e]xceptions are
made to the ‘no credit for voluntary overpayment rule’ when
the equities of the circumstances demand it and when allow-
ing a credit will not work a hardship on the minor children.”
Id. at 115, 608 N.W.2d at 224. Nebraska appellate courts have
generally considered the application of overpayment credits as
a question of law. See, Jensen v. Jensen, 275 Neb. 921, 750
N.W.2d 335 (2008); Jameson v. Jameson, 13 Neb. App. 703,
700 N.W.2d 638 (2005).
   In determining that Kari was not entitled to the relief pro-
vided by the district court, the Court of Appeals cited to Griess
v. Griess, supra. The Court of Appeals acknowledged that it
had decided that the relief of a credit against future support
payments was appropriate in Griess, because the trial court
had entered a grossly erroneous modification order that was
prepared by the attorney for the party receiving the child sup-
port and the attorney for the paying party had overlooked,
ignored, and implicitly approved the erroneous calculation. The
Court of Appeals distinguished the present case from Griess
primarily on the basis that Kari’s claimed overpayment was
not the result of a mistake but was an amount to which he had
agreed in the stipulated decree. Because Kari had agreed to the
$3,000, the Court of Appeals reasoned that Kari was precluded
                   Nebraska Advance Sheets
	                      JOHNSON v. JOHNSON	857
	                        Cite as 290 Neb. 838

from receiving a credit and that the district court had erred
when it had found Kari eligible for a credit.
   On the record before us, we disagree with the Court of
Appeals’ application of Griess and determine that upon remand,
Kari is not ineligible for a credit for overpayment of child sup-
port that may be found on remand. The determination of Kari’s
entitlement to a credit, if any, will necessarily be made by the
district court upon remand based on a more developed record
regarding the parties’ relative incomes.
   Our jurisprudence permits a credit for overpayment under
the circumstances of this case. See, Jensen v. Jensen, supra
(stating that credit against child support is permissible where
equity requires it, citing Griess); Jameson v. Jameson, supra
(quoting rule in Griess but finding it inapplicable); Griess v.
Griess, supra. Other jurisdictions are in accord with Nebraska
jurisprudence and have allowed a credit for overpayments made
under earlier, higher child support orders, after a later retroac-
tive modification reduced the child support order. See, e.g.,
In re Marriage of Frazier, 205 Ill. App. 3d 621, 563 N.E.2d
1236, 151 Ill. Dec. 130 (1990) (after reducing obligor father’s
child support obligations retroactively to date of his petition
for modification, court allowed father credit against ongoing
child support obligations for having paid higher child sup-
port amounts due prior to modification); Annot., 7 A.L.R.6th
411 (2005).
   We believe the circumstances in this case permit the award
of a credit upon remand for overpayment of child support
if, upon application of the child support guidelines, and in
the absence of hardship, the district court finds an overpay-
ment has been made during the pendency of the modification
proceedings. We find it relevant the record shows that Kari
repeatedly attempted to lower his obligation during the pend­
ency of the modification process, but that his efforts were
unsuccessful, due in part to Elizabeth’s resistance and delay
in processing the case. Kari filed his application for modifi-
cation in September 2011, but the last order disposing of the
application was not filed until August 2013. Trial was initially
set for April 10, 2012. Prior to trial, the parties reported that
    Nebraska Advance Sheets
858	290 NEBRASKA REPORTS



they had “settled” the matter. However, after the trial date
had passed, according to the pleadings, Elizabeth repudiated
the settlement. On September 6, Kari sought temporary abate-
ment of child support. On September 11, the pretrial order set
the trial for January 24, 2013. On October 19, 2012, prior to
the new trial date, Kari filed a motion to temporarily reduce
his child support and a motion for credit. Elizabeth sought
and obtained a continuance of Kari’s temporary motions. The
district court ordered that Kari’s temporary motions were to
be addressed at the modification trial, and the trial was set
for January 2013. So, Kari continued to abide by the original
order of $3,000 per month.
   Our appellate jurisprudence has addressed the efforts an
obligor parent has made during the pendency of a motion to
modify a child support obligation. In Lucero v. Lucero, 16
Neb. App. 706, 750 N.W.2d 377 (2008), the Court of Appeals
indicated that the obligor parent’s failure to seek relief dur-
ing the pendency of the case weighed against granting credit.
The Court of Appeals stated: “[The ex-husband] could have
sought and likely obtained a temporary order upon motion
and affidavit, suspending his payments pending the final
hearing on his request to terminate child support payments
rather than paying them and hoping to get them back from
his financially distressed ex-wife.” Id. at 720, 750 N.W.2d
at 388. Unlike the obligor in Lucero, Kari made repeated
attempts to lower his child support obligation during the
pend­ ency of the modification. His efforts to obtain relief
sooner should be recognized.
   We have observed, in the context of retroactive modifica-
tion, that parties ought not be penalized by delay in the legal
process. See Pursley v. Pursley, 261 Neb. 478, 623 N.W.2d
651 (2001). We logically apply the principle to our consider-
ation of granting a credit. Although Kari was not subject to a
grossly erroneous child support order like the obligor in Griess
v. Griess, 9 Neb. App. 105, 608 N.W.2d 217 (2000), we believe
the exception in Griess is applicable to the facts of this case
and makes Kari eligible for a credit.
                  Nebraska Advance Sheets
	                     JOHNSON v. JOHNSON	859
	                       Cite as 290 Neb. 838

               (c) Judgment Against Elizabeth for
               Anticipated Unused Child Support
                        Overpayment Credit
   The district court found that Kari had overpaid child sup-
port during the pendency of the modification proceedings,
and ordered that the overpayment serve as a credit for Kari’s
obligations during the pendency of the modification proceed-
ings and during the remainder of the children’s minority. The
district court calculated that the overpayment would not be
exhausted and entered judgment against Elizabeth for the antic-
ipated unused overpayment. The Court of Appeals reversed
the judgment in part, because “there was no showing [that
Elizabeth] has the means to pay” the approximately $23,114.21
portion of the judgment attributable to the anticipated unused
overpayment. Kari claims the Court of Appeals erred when it
reversed the judgment against Elizabeth for the future unused
overpayment of child support. Although our reasoning dif-
fers somewhat from that of the Court of Appeals, we find
no error and affirm the reversal of the judgment attributable
to the anticipated unused child support credit. Upon remand,
the district court is instructed that entry of a judgment against
Elizabeth for future anticipated unused overpayment is not per-
mitted under Nebraska jurisprudence.
   The judgment under review suffers from the same weak-
nesses as do lump-sum child support judgments in satisfac-
tion of future payments, which are disfavored in Nebraska. In
Gibson v. Gibson, 147 Neb. 991, 26 N.W.2d 6 (1947), the trial
court awarded, in advance, all the child support to be paid for
the following 13 years. On appeal, this court observed that
child support is at all times subject to change and that the
Nebraska Legislature had provided for such changes by allow-
ing for modification of child support. In Gibson, we reasoned
that lump-sum awards of child support are not supported by the
law, because the modification statute “would be entirely inef-
fective if such a final judgment could be entered as was done
in this case.” 147 Neb. at 1000, 26 N.W.2d at 10. In Gibson,
we stated:
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         It is improper under the law to make a final, definite,
      and positive entry of such a judgment for the support of
      a minor child, for the amount to be paid must vary with
      the several needs of the child for food, clothing, and
      expenses involved in his education, with his necessary
      medical and surgical requirements, and the court may
      also consider such changes in the financial condition
      of the father [obligor] as are shown by the testimony.
      Therefore, the law has provided that the monthly pay-
      ments can be changed from time to time as the evi-
      dence warrants.
147 Neb. at 1000, 26 N.W.2d at 10. See, similarly, Gress v.
Gress, 257 Neb. 112, 117, 596 N.W.2d 8, 13 (1999) (discuss-
ing credits, wherein we stated: “Future obligations are not yet
accrued, and because they are subject to modification, they are
not ascertainable”). For completeness, we note that although
lump-sum child support awards are not favored under the
law in Nebraska, an obligor may receive credit against future
obligations for payments already made, including a lump-sum
payment already made where such payment does not preclude
future child support awards or adjustments. Jensen v. Jensen,
275 Neb. 921, 750 N.W.2d 335 (2008).
   In the present case, the district court’s judgment against
Elizabeth was based on its assumption as calculated in 2013
that there would be no changes to the child support obliga-
tions of the parties throughout the remainder of the children’s
minority ending in 2017. The assumption that there will be
no further modifications is not correct and contrary to law.
Our reasoning in Gibson still applies. Therefore, we agree
with the Court of Appeals that the lump-sum judgment against
Elizabeth for the anticipated unused child support credit should
be reversed.
   In sum, on remand, the amount of the parties’ child support
obligations shall be calculated based, in part, on a determina-
tion of Elizabeth’s wage-earning capacity that is supported
by competent evidence in the record, the Social Security ben-
efits received by the children are to be considered a gratuity,
and Kari is not to receive a credit therefor. Given the record
and equities, we conclude that modification of Kari’s child
                  Nebraska Advance Sheets
	                     JOHNSON v. JOHNSON	861
	                       Cite as 290 Neb. 838

support obligation retroactive to October 2011 is permissible.
In the event that the district court determines that Kari has
overpaid child support during the pendency of the modifica-
tion proceedings, Kari is eligible to receive a credit. Such
credit may be applied against future child support obligations
on a month-to-month basis. However, because our jurispru-
dence disfavors lump-sum final child support judgments, we
reverse the district court’s judgment against Elizabeth for
$25,472.11, which included $23,114.21 of Kari’s anticipated
unused overpayment credit, and we remand the cause with
directions in accordance with this opinion.

               (d) Judgment Regarding American
                     Express Reimbursement
   The $25,472.11 judgment entered by the district court was
composed of $23,114.21 attributable to the impermissible
award against Elizabeth for Kari’s anticipated future unused
child support overpayment credit and $2,357.90 attributable
to the withdrawal that Elizabeth made from Kari’s account,
which she used to pay an American Express bill. The Court of
Appeals disapproved of the $23,114.21 portion and approved
of the $2,357.90 portion, as do we.
   We have reversed the district court’s judgment of $25,472.11
against Elizabeth. However, that judgment included $2,357.90
that Elizabeth withdrew from an account of Kari’s to pay an
American Express bill. The parties do not dispute the propriety
of that portion of the judgment, and it is supported by evidence
in the record. Accordingly, on remand, we order the district
court to enter a judgment against Elizabeth in the amount
of $2,357.90.

                      VI. CONCLUSION
   For the foregoing reasons, on further review, we conclude
as follows: (1) The Court of Appeals correctly determined
that the district court erred when it imputed to Elizabeth a
wage-­earning capacity of $52,000 per year and reversed the
order and remanded the cause for a hearing on Elizabeth’s
wage-earning capacity, and we affirm this decision; (2) the
Court of Appeals did not err when it affirmed the district
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court’s conclusion that the Social Security benefits paid to
the children were a gratuity and that Kari should not be given
a credit upon remand, and we affirm this decision; and (3)
although the Court of Appeals correctly affirmed the district
court’s decisions that a downward modification in Kari’s child
support could be retroactive to the month after the filing of
the application to modify, that the judgment against Elizabeth
for $25,472.11 should be reversed, that a judgment against
Elizabeth for $2,357.90 should be entered, and we affirm
these decisions, it erred when it reasoned that upon remand,
Kari could not receive credit for overpayments, if any, made
during the pendency of the modification proceedings for the
reason that Kari had continued to pay the $3,000-per-month
child support ordered in the decree. To the contrary, the fact
that Kari continued to pay what had been ordered does not
preclude consideration of a potential credit after receipt of
additional evidence upon remand pursuant to the exception in
Griess v. Griess, 9 Neb. App. 105, 608 N.W.2d 217 (2000).
Accordingly, we affirm in part, and in part reverse and remand
with directions.
	Affirmed in part, and in part reversed
	                      and remanded with directions.




   State    of   Nebraska,     appellee, v.Craig Anthony Johnson,
            also known as        Craig A. Johnson, appellant.
                                   ___ N.W.2d ___

                        Filed May 15, 2015.     No. S-14-101.

 1.	 Appeal and Error. For an appellate court to consider an alleged error, a party
     must specifically assign and argue it.
 2.	 Juries: Discrimination: Equal Protection: Prosecuting Attorneys. A prosecu-
     tor ordinarily is entitled to exercise permitted peremptory challenges for any
     reason at all, if that reason is related to his view concerning the outcome of the
     case. But under Batson v. Kentucky, 476 U.S. 79, 106 S. Ct. 1712, 90 L. Ed. 2d
     69 (1986), a peremptory challenge to remove a prospective juror for a racially
     discriminatory reason violates the Equal Protection Clause.
 3.	 Juries: Discrimination: Prosecuting Attorneys: Proof. Determining whether a
     prosecutor impermissibly sought to remove a prospective juror based on race is
