                     FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                        No. 04-50493
                Plaintiff-Appellee,
               v.                                  D.C. No.
                                                CR-03-02294-NAJ
ABISAI RIVERA-GUERRERO,
                                                   OPINION
             Defendant-Appellant.
                                           
         Appeal from the United States District Court
           for the Southern District of California
         Napoleon A. Jones, District Judge, Presiding

                    Argued and Submitted
            January 10, 2005—Pasadena, California

                      Filed October 19, 2005

        Before: Stephen Reinhardt, Richard R. Clifton,
           Circuit Judges, and Charles R. Weiner,*
                     Senior District Judge.

                   Opinion by Judge Reinhardt




   *The Honorable Charles R. Weiner, Senior United States District Judge
for the Eastern District of Pennsylvania, sitting by designation.

                                14319
              UNITED STATES v. RIVERA-GUERRERO            14323


                         COUNSEL

Zandra L. Lopez, Federal Defenders of San Diego, San
Diego, California, for the defendant-appellant.

Carol C. Lam, United States Attorney; Roger W. Haines, Jr.,
Assistant U.S. Attorney (On the Briefs); Garrett M. Heenan,
Assistant U.S. Attorney, San Diego, California (Argued), for
the plaintiff-appellee.


                          OPINION

REINHARDT, Circuit Judge:

   This appeal involves questions relating to the involuntary
medication of a defendant awaiting trial in federal court. After
being arrested and charged with illegal entry, defendant Abi-
sai Rivera-Guerrero was found incompetent to stand trial. Fol-
lowing his commitment to the Federal Medical Center
(“FMC”) pursuant to an order dated November 4, 2003, the
FMC doctors requested that the district court issue another
order permitting him to be involuntarily medicated with antip-
sychotic drugs for the purpose of restoring his competency so
that he could stand trial. The court ordered that a hearing be
held. When the hearing began, the magistrate judge decided
that it would be held pursuant to Sell v. United States, 539
U.S. 166 (2003) rather than Washington v. Harper, 494 U.S.
210 (1990). After the government’s witnesses, two FMC doc-
tors, testified, defendant’s counsel requested a continuance so
that she could prepare her rebuttal. The district court denied
the request and issued an order permitting involuntary medi-
14324            UNITED STATES v. RIVERA-GUERRERO
cation. On October 4, 2004, the order was ultimately reaf-
firmed by the district court upon remand.

   We now reverse the district court’s denial of the continu-
ance, vacate the involuntary medication order, and remand
with instructions that in light of intervening events the district
court obtain a report on Rivera-Guerrero’s present mental
condition and proceed in accordance with the second and
third sentences of 18 U.S.C. § 4241(d). In so doing, the dis-
trict court shall treat the “reasonable period of time” for which
the Attorney General may maintain him in custody under that
subsection as having expired. The order of commitment to the
FMC shall be of no further force and effect.

      FACTUAL BACKGROUND AND PROCEDURAL HISTORY

   Rivera-Guerrero was arrested on September 14, 2003 and
charged with illegal entry after deportation pursuant to 8
U.S.C. § 1326(a). After undergoing a psychological examina-
tion, he was found incompetent to stand trial, just as he had
been on two previous occasions. As a result, the district court
delivered him to the custody of the Attorney General so that
he could be “hospitalize[d] . . . for . . . a reasonable period of
time not to exceed four months . . . to determine whether there
is a substantial probability that in the foreseeable future” he
would become competent to stand trial. 18 U.S.C. § 4241(d)(1).1
Rivera-Guerrero was committed to the Federal Medical Cen-
ter (“FMC”) in Springfield, Missouri in November of 2003.

   On February 6, 2004, Dr. Sarrazin and Dr. Mrad, doctors
from the FMC, appeared before a magistrate judge to discuss
the need to involuntarily medicate Rivera-Guerrero. Dr. Mrad
  1
   After the expiration of the initial four month period, the statute allows
for any additional “reasonable period of time” if the district court finds
that there is a “substantial probability that within such additional period
of time he will attain the capacity to permit the trial to proceed.” 18
U.S.C.A. § 4241(d)(2)(A).
                 UNITED STATES v. RIVERA-GUERRERO                    14325
explained that the defendant refused to consent to the admin-
istration of antipsychotic medication, without which he could
not be rendered competent. Following the doctors’ presenta-
tion, the magistrate judge scheduled a hearing to determine
Rivera-Guerrero’s medical condition, the legal standard to be
applied when adjudicating the FMC’s request for an involun-
tary medication order, and the appropriateness of such an
order.

   Two weeks later, after briefing by the parties as to the
appropriate standard, the magistrate judge held another hear-
ing to determine finally the question of the applicable law. At
the urging of both parties, the court decided to apply Sell,
which pertains to involuntary medication for the purpose of
restoring a defendant’s competency for trial, rather than Har-
per, which also pertains to involuntary medication but
involves the element of dangerousness. Dr. Sarrazin testified
that the defendant suffered from a form of psychosis, possibly
schizophrenia, and that consequently, only medication could
render defendant competent. Dr. Sarrazin stated that Rivera-
Guerrero could be safely medicated because he planned on
experimenting with several different drugs — starting with
“atypical” antipsychotics and moving to “typicals,” if neces-
sary, in light of the side-effects.2 For example, Dr. Sarrazin
suggested administering one of the newer atypical drugs, such
as risperidone, which he acknowledged could cause nausea,
cognitive clouding, sedation, tardive dyskinesia,3 and diabe-
  2
     Antipsychotic medication is currently divided into two categories:
“typicals” and “atypicals.” Typicals are older medications that were relied
upon extensively during the latter half of the 20th century to treat psycho-
sis. Atypicals are the next generation of antipsychotics. There is some evi-
dence that atypicals cause less side-effects than typicals. However, some
believe that atypicals are at best no better than the typicals, and at worst,
responsible for a different set of potentially more dangerous side-effects.
   3
     “Tardive dyskinesia is a neurological disorder, irreversible in some
cases, that is characterized by involuntary, uncontrollable movements of
various muscles, especially around the face.” Harper, 494 U.S. at 230
(emphasis added).
14326         UNITED STATES v. RIVERA-GUERRERO
tes. If one of the atypicals produced intolerable side effects,
Dr. Sarrazin continued, he would slowly change Rivera-
Guerrero’s medical regime to another atypical. If Rivera-
Guerrero refused medication in contravention of a court order,
then the doctor would select a drug that could be forcibly
injected.

   Dr. Sarrazin did not state that such experimentation would
have a significant likelihood of rendering the defendant
legally competent. Instead, he explained that according to a
Bureau of Prisons study, “about 76 percent or so [of the
patients] that were involuntarily medicated were restored to
competency.” He could not say that he had enjoyed this kind
of success rate with his own patients or, more important, with
any of the drugs that he proposed. Indeed although Dr. Sar-
razin explained that these medications would be very helpful
in “the treatment of [the defendant’s] underlying mental ill-
ness and his delusions,” it would only be after the drug had
already been administered and its effects known “that [the
FMC] would be able to tell more about his competency.”
Moreover, Dr. Sarrazin acknowledged that despite the variety
of drugs that he proposed, in his personal experience they had
been successful in restoring to competency only three
patients. Following Dr. Sarrazin’s testimony, Dr. Mrad told
the court that it was his opinion also that only medication
could restore Rivera-Guerrero’s competency. He specifically
rejected all alternative forms of treatment.

  At the conclusion of the hearing, counsel for Rivera-
Guerrero asked the magistrate judge for a continuance so that
she could consult independent doctors about the drugs that Dr.
Sarrazin proposed using and obtain an independent expert
medical opinion regarding the effectiveness and medical
appropriateness of the FMC’s suggested course of treatment.
Counsel intended to use the continuance to interview doctors,
and help prepare a medical expert who would rebut the testi-
mony of the FMC physicians. The magistrate judge denied
counsel’s request, proceeded directly to her decision, and
               UNITED STATES v. RIVERA-GUERRERO            14327
found the evidence sufficient to justify involuntary medica-
tion. She then issued an order authorizing Rivera-Guerrero’s
involuntary medication and extended his commitment at the
FMC for an additional four months pursuant to 18 U.S.C.
§ 4241(d)(1).

   After the issuance of the involuntary medication order,
defense counsel promptly appealed it to a district judge —
alleging that the magistrate judge lacked the constitutional
and statutory authority independently to issue an order for
involuntary medication. She also appealed the magistrate
judge’s determination on the merits. Counsel presented the
district court with several articles describing the powerful,
fatal, and trial-related side-effects of antipsychotic medica-
tion. The district judge then made several rulings. He dis-
missed the articles on hearsay grounds because no medical
expert had been retained to lay the foundation for their intro-
duction into evidence, and affirmed the magistrate judge’s
denial of Rivera-Guerrero’s request for a continuance, thus
foreclosing the defendant from presenting any independent
medical expert. He also upheld the authority of the magistrate
judge and affirmed the order on the merits under a clear error
standard.

   Counsel for Rivera-Guerrero then filed an appeal to this
court. Without reaching the merits, we vacated the magistrate
judge’s order on the ground that “an involuntary medication
order is not the type of pretrial matter the Federal Magistrates
Act permits district courts to delegate final authority to magis-
trate judges.” United States v. Rivera-Guerrero, 377 F.3d
1064, 1071 (2004). As a result, the district court’s decision
was vacated with instructions that the district judge review the
merits of the magistrate judge’s decision de novo instead of
for clear error.

   Following our remand, the district court received a letter
from the FMC stating that on August 31, 2004, medical per-
sonnel involuntarily medicated Rivera-Guerrero in an emer-
14328         UNITED STATES v. RIVERA-GUERRERO
gency procedure pursuant to 28 C.F.R. § 549.43(b). The letter
also stated that the FMC will continue to involuntarily medi-
cate Rivera-Guerrero “unless or until the Court advises them
to stop.” In response to this new development, counsel for
Rivera-Guerrero requested an evidentiary hearing to explore
the facts behind the emergency medication and the effects, if
any, the medication had on Rivera-Guerrero’s competency.
Counsel also explained that the evidentiary hearing was nec-
essary to update the court on the medical condition of Rivera-
Guerrero, whom defense counsel had not seen in almost a
year. The request, however, was denied by the district court.

   On October 4, 2004, the district judge issued an opinion
adopting the recommendations of the magistrate judge for rea-
sons nearly identical to those contained in the order we had
previously vacated. He denied a stay in part because he con-
cluded that the emergency medication of Rivera-Guerrero
rendered the order’s provisions moot. This court denied a stay
as well. Rivera-Guerrero appeals the district court’s October
4th order.

                         DISCUSSION

A.   The Law of Involuntary Medication

   Although we resolve this appeal on the ground that the dis-
trict court erred in failing to grant the defendant a continu-
ance, the law regarding involuntary medication guides our
determination on that question. The Supreme Court’s refusal
to permit involuntary medication except in highly-specific
factual and medical circumstances illustrates the importance
of a complete factual and medical record upon which a judge
can base his decision. Recognizing what is at stake, we must
be vigilant in our review of procedural rulings that deny the
defendant an opportunity to challenge the government’s case.

   “The Supreme Court has thrice recognized a ‘liberty inter-
est in freedom from unwanted antipsychotic drugs.’ ” United
               UNITED STATES v. RIVERA-GUERRERO            14329
States v. Williams, 356 F.3d 1045, 1053 (9th Cir. 2004) (quot-
ing Riggins v. Nevada, 504 U.S. 127, 137 (1992)). In Wash-
ington v. Harper, the Court held that prisoners “possess[ ] a
significant liberty interest in avoiding the unwanted adminis-
tration of antipsychotic drugs under the Due Process Clause
of the Fourteenth Amendment.” 424 U.S. at 221. It explained
that involuntary medication is permitted only for “inmates
who are . . . gravely disabled or represent a significant danger
to themselves or others,” id. at 226, and only after the court
is satisfied that the medication would be “in the prisoner’s
medical interests, given the legitimate needs of his institu-
tional confinement.” Id. at 222.

   Two years later in Riggins v. Nevada, the Court again pro-
claimed that an individual has a constitutionally protected
right to “avoid[ ] involuntary administration of antipsychotic
drugs,” only this time in the context of a criminal defendant
facing trial. 504 U.S. at 134. The defendant who was involun-
tarily medicated pending trial challenged his ensuing convic-
tion; he alleged that because he was forced by the state to
continue his antipsychotic medication even after he had
decided that he no longer wished to do so, he was prejudiced
by the subtle but significant effects of the anti-psychotic drug
upon his demeanor and his ability to testify at trial. See id. at
132. The Supreme Court agreed. It reversed the defendant’s
murder conviction, holding that the record before the state
court failed to justify its involuntary medication order, and
that there was a likelihood that the defendant was prejudiced
by the drug. Id. at 137.

    [1] Most recently in Sell v. United States, 539 U.S. 166
(2003), the Supreme Court, extrapolating from Harper and
Riggins, held that the “Constitution permits the Government
involuntarily to administer antipsychotic drugs to a mentally
ill defendant facing serious criminal charges in order to render
that defendant competent to stand trial, but only if the treat-
ment is “medically appropriate, i.e., in the patient’s best med-
ical interest in light of his medical condition,” id. at 181
14330          UNITED STATES v. RIVERA-GUERRERO
(emphasis in original), is substantially unlikely to have side
effects that may undermine the fairness of the trial, and, tak-
ing account of less intrusive alternatives, is necessary signifi-
cantly to further important governmental trial-related
interests,” id. at 179. Noting that the case was dissimilar to
Harper in that in Sell the government’s only proffered interest
in involuntary medication was to render the defendant compe-
tent to stand trial, the Court explained that unlike in Harper,
the decision was not entirely medical in nature. Indeed,
according to the Court, the “balanc[ing of] harms and bene-
fits” required by Sell “related to the more quintessentially
legal questions of trial fairness and competence.” Id. at 182.
Subsequent to Sell, we held that in light of the importance of
judicial balancing, and the implication of deep-rooted consti-
tutional rights, a court that is asked to approve involuntary
medication must be provided with a complete and reliable
medically-informed record, based in part on independent
medical evaluations, before it can reach a constitutionally bal-
anced Sell determination. See Williams, 356 F.3d at 1056 (cit-
ing Harper, 494 U.S. at 233-35 (emphasizing the necessity for
independent medical decisionmaking in the context of invol-
untary medication)).

   Sell orders are disfavored. The Supreme Court clearly
intends courts to explore other procedures, such as Harper
hearings (which are to be employed in the case of dangerous-
ness) before considering involuntary medication orders under
Sell. The Sell Court explained that “[t]here are often strong
reasons for a court to determine whether forced administration
of drugs can be justified on . . . alternative grounds before
turning to the trial competence question.” Sell, 539 U.S. at
182 (emphasis in original). It preferred the dangerousness
inquiry under Harper because that inquiry is ordinarily more
“objective and manageable” than one based entirely on the
interest of the government in rendering a defendant competent
to stand trial. Id. (quoting Riggins, 504 U.S. at 140) (internal
quotation marks omitted). The Court explained that even if
the government requests an order on Sell grounds, a judge
                 UNITED STATES v. RIVERA-GUERRERO                    14331
should “ordinarily determine whether the Government seeks,
or has first sought, permission for forced administration of
drugs on these other Harper-type grounds; and, if not, why
not.” Id.4

   [2] Harper, Riggins, and Sell demonstrate the Court’s
reluctance to permit involuntary medication except in rare cir-
cumstances. See e.g., Sell, 539 U.S. at 180 (noting that while
the Sell “standard . . . permit[s] involuntary administration of
drugs solely for trial competence purposes in certain
instances[,] . . . those instances may be rare.” (emphasis
added)); Riggins, 504 U.S. at 127 (explaining that involuntary
medication is “impermissible absent a finding of overriding
justification”). The importance of the defendant’s liberty
interest, the powerful and permanent effects of anti-psychotic
medications, and the strong possibility that a defendant’s trial
will be adversely affected by the drug’s side-effects all coun-
sel in favor of ensuring that an involuntary medication order
is issued only after both sides have had a fair opportunity to
present their case and develop a complete and reliable record.

B. Denial of a Continuance and the Need for an Evidentiary
Hearing

   The dispositive question on this appeal is whether the dis-
trict court abused its discretion in denying the defendant’s
request for a continuance. The defendant sought the continu-
ance so that he could obtain the services of a medical expert
who would be able to rebut the testimony of the two FMC
doctors. The district court’s ruling deprived him of an “inde-
pendent . . . evaluation . . . by a medical professional . . . as
  4
   The record strongly suggests that in the case before us the district court
should have conducted a Harper dangerousness hearing instead of pro-
ceeding under Sell. Nevertheless, in light of our decision to remand on
other grounds and the subsequent change in circumstances, including the
emergency administration of involuntary medication and the substantial
passage of time, we need not decide that issue here.
14332          UNITED STATES v. RIVERA-GUERRERO
well as an opportunity . . . to challenge the evaluation and
offer his or her own medical evidence in response.” Williams,
356 F.3d at 1056. Indeed, the continuance resulted in the
defendant’s inability to present any evidence that might rebut
the government’s medical assertions. Because defendant’s
counsel acted reasonably in relation to preparing for the hear-
ing, a continuance was important to her presentation of an
adequate defense, the record fails to reflect that a continuance
would have caused any substantial inconvenience to the court
or the parties, and the defendant was prejudiced by the denial
of a continuance, we hold that the district court abused its dis-
cretion in denying the defendant’s request.

   [3] A district court’s denial of a continuance is reviewed for
an abuse of discretion. Reversal is required if “after carefully
evaluating all the relevant factors,” we conclude that “the
denial was arbitrary or unreasonable.” See United States v.
Flynt, 756 F.2d 1352, 1358 (9th Cir 1985). “There are no
mechanical tests for deciding when a denial of a continuance
is so arbitrary as to violate due process. The answer must be
found in the circumstances present in every case, particularly
in the reasons presented to the trial judge at the time the
request is denied.” Ungar v. Sarafite, 376 U.S. 575, 589
(1964). Although we have stated that our inquiry is not
mechanical, we have developed a four factor test to guide our
analysis, which includes:

    [1] the extent of appellant’s diligence in his efforts
    to ready his defense prior to the date set for hearing
    . . . [2] how likely it is that the need for a continu-
    ance could have been met if the continuance had
    been granted . . . [3] the extent to which granting the
    continuance would have inconvenienced the court
    and the opposing party, including its witnesses . . .
    [4] the extent to which the appellant might have suf-
    fered harm as a result of the district court’s denial.

Flynt, 756 F.2d at 1359. None of the first three factors is ordi-
narily dispositive. The defendant must, however, establish the
                 UNITED STATES v. RIVERA-GUERRERO                    14333
fourth — prejudice. Id. Here, our assessment of the Flynt fac-
tors reveals that at least three of them, including the prejudice
factor, support reversal of the district court’s order.

  i.   Diligence

   The first factor we consider is diligence. The government
argues that the district court’s denial of Rivera-Guerrero’s
request for a continuance was proper because the defendant’s
need for the continuance was caused by counsel’s lack of dili-
gence in preparing his defense. The government points out
that the magistrate judge denied defendant’s request for a con-
tinuance because, “[t]he defense was aware of this hearing,
the nature of the hearing, the date of the hearing,” and should
have presented its expert rebuttal evidence at the hearing. The
district court, in reviewing the magistrate judge’s decision,
affirmed the denial on the same ground.

   [4] The diligence factor does not play a significant role in
our resolution of this appeal. Even if we assume that defense
counsel’s preparation was not exemplary and that counsel
could have obtained the services of a medical expert prior to
the hearing,5 defendant’s request for additional time should
have been granted. Had the defendant retained an expert for
  5
    It is unclear that defense counsel had the information necessary to
secure a competent expert before the February 19th hearing, given the lack
of specific information provided prior to that date. When counsel asked
the FMC doctors at the February 6th hearing which specific drugs would
be used in the course of treatment, Dr. Sarrazin simply offered a list of the
available drugs — including Alanzapin, Risperidone, Perazidone,
Haloperidol and Phuphesedene — instead of identifying the specific drug
or drugs that the FMC intended to administer. Dr. Sarrazin went on to con-
firm that he would not be able to say “at this point . . . exactly what medi-
cation” would be used and that often, many medications may be attempted
before finding one that is effective. Indeed, it was not until the hearing
itself that the doctors from the FMC committed to starting with Risperi-
done, and then to use injectable Geodon (which was not mentioned in the
initial conference) or Haloperidol after that, if the FMC could not orally
administer the medication.
14334             UNITED STATES v. RIVERA-GUERRERO
the hearing, the expert would have needed additional time to
review the specific course of treatment recommended by the
FMC’s doctors and the medical consequences of treating the
particular defendant in the manner prescribed, because those
recommendations were not disclosed prior to the hearing.6

    As the Supreme Court has explained, at a Sell hearing the
court is required to consider specific drugs, their unique side
effects, and their medical appropriateness. Specificity as to
the medications to be administered is critical. See Sell, 539
U.S. at 181 (“The specific kinds of drugs at issue may matter
. . . [because d]ifferent kinds of antipsychotic drugs may pro-
duce different side effects and enjoy different levels of suc-
cess.” (emphasis added)); id. at 185 (“Whether a particular
drug will tend to sedate a defendant, interfere with communi-
cation with counsel, prevent rapid reaction to trial develop-
ments, or diminish the ability to express emotions are matters
important in determining the permissibility of medication to
restore competence.” (citing Riggins, 504 U.S. at 142-45)
(emphasis added). Counsel for Rivera-Guerrero attempted to
  6
   To avoid this kind of surprise at trial, and to ensure that proper
responses to, and effective cross examination of, expert testimony can be
secured, the federal rules require the government, when asked, to provide
a written opinion of every expert it plans to call. See Fed. R. Crim. P.
16(a)(1); see also, Fed. R. Civ. P. 26(a)(2) (providing for advance disclo-
sure of expert reports in civil cases). Indeed, the Advisory Committee
Notes to this Rule explain that it
      is intended to minimize surprise that often results from unex-
      pected expert testimony, reduce the need for continuances, and to
      provide the opponent with a fair opportunity to test the merit of
      the expert’s testimony through focused cross examination.
Fed. R. Crim. P. 16 advisory committee’s note; cf. United States v. Kelly,
420 F.2d 26, 28 (2nd Cir. 1969) (“Indeed, it is important that the defense
be given a chance to research the techniques and results of scientific tests
taken by the government.”). Rivera-Guerrero’s Sell hearing was not an
actual trial, and is therefore not subject to Rule 16. We note, however, that
counsel’s lack of knowledge about the specific drugs and the proposed
course of treatment until the day of the hearing is precisely the type of pre-
dicament that Rule 16 tried to eliminate.
                  UNITED STATES v. RIVERA-GUERRERO                     14335
procure such necessary specific information in advance in
order to provide an adequate rebuttal, only to be given a non-
specific and unhelpful general listing of available medications
by the FMC doctors before the magistrate judge terminated
the inquiry. Thus, it was not until the Sell hearing itself that
counsel was able to obtain the necessary information regard-
ing the FMC’s plans and intentions. We have held that “fair-
ness requires that adequate notice be given the defense to
check the findings and conclusions of the government’s
experts.” United States v. Barrett, 703 F.2d 1076, 1081 (9th
Cir. 1982) (quoting United States v. Kelly, 420 F.2d 26, 29
(2nd Cir. 1969) (internal quotation marks omitted)). That was
not the case here.

   [5] We reject, therefore, the district court’s determination
that the defendant’s request for a continuance was necessi-
tated by her own lack of diligence. Furthermore, even if coun-
sel’s request for a continuance had been due in some measure
to a lack of diligence, that finding would not end our inquiry.
The four-factor test of Flynt is not mechanically applied. We
have reversed a district court’s denial of a continuance even
after concluding that the defendant failed the diligence prong
of the analysis. See United States v. 2.61 Acres of Land, More
or Less, Situated in Mariposa County, State of Cal., 791 F.2d
666, 671-72 (9th Cir. 1985); see also Flynt, 756 F.2d at 1359
(“The weight . . . attribute[d] to any single factor may vary
with the extent of the showings on the other factors.”).7
Accordingly, we turn our attention now to the remaining fac-
tors to be considered under Flynt.
  7
    Moreover, if the district court should have been aware of the need for
a continuance to permit the defendant to get a medical evaluation, the
denial of the continuance request may constitute an abuse of discretion
even if the failure to obtain the evidence earlier resulted from a lack of dil-
igence on the defendant’s part. See United States v. Pope, 841 F.2d 954,
956-57 (9th Cir. 1988) (“the court’s colloquy with Pope should have
alerted the court to the defendant’s flawed perception of reality and should
have underscored the importance of a continuance to enable the defense
to secure a psychiatric evaluation.”).
14336             UNITED STATES v. RIVERA-GUERRERO
  ii.   Utility

  [6] Next, we consider the utility of granting a continuance.
Would the continuance have resulted in the production of rel-
evant evidence? See Flynt, 756 F.2d at 1360. When requesting
a continuance, a defendant is not required to demonstrate
what specific evidence he would present if a continuance
were granted; rather, a showing that evidence helpful to his
position could be produced is sufficient. “To require any
greater specificity under these circumstances would not have
been reasonable.” Id.

   [7] Rivera-Guerrero’s counsel informed the district court
that probative evidence could be available if a continuance
were granted, and described the type of evidence she would
present. Substantial rebuttal evidence against involuntary
medication was available to counsel had she been allowed
time to prepare her client’s defense. This is demonstrated by
the large collection of articles expressing views contrary to
those presented by the FMC that the defendant offered to the
district court. See e.g., Robert Whitaker, The Case Against
Antipsychotic Drugs: A 50-year Record of Doing More Harm
than Good, 62 Med. Hypotheses 5 (2004) (arguing that treat-
ing many patients without antipsychotic medication would
increase recovery rates and decrease chronic illness); Maurice
Rappaport, et al., Are There Schizophrenics for Whom Drugs
May be Unnecessary or Contraindictated?, 13 INT’L PHAR-
MACOPSYCHIATRY 100 (1978) (arguing for selective utilization
of antipsychotic medication and reporting a number of schizo-
phrenics who do relatively well long term without routine or
continuous medication).8 These articles suggest that a respect-
  8
    Reviewing the medical literature on antipsychotic medication, some
Supreme Court justices have also acknowledged the potential harmful
effects of antipsychotics. See Harper, 494 U.S. at 239 (1990) (Stevens, J.,
concurring in part and dissenting in part) (noting that antipsychotics “alter
the chemical balance in a patient’s brain,” “can cause irreversible and fatal
side effects,” and “[t]he risk of side effects increases over time”); Riggins,
504 U.S. at 138-39 (Kennedy, J., concurring) (“fil[ing a] separate opinion
. . . to express doubt that the showing [necessary to support involuntary
medication] can be made in most cases, given our present understanding
of the properties of these drugs.”)
               UNITED STATES v. RIVERA-GUERRERO            14337
able, though minority, portion of the medical community
strongly believes that antipsychotic medications cause long-
term and irreversible harm and have a high chance of produc-
ing trial-related and even fatal side-effects, and that such
drugs are not universally considered medically appropriate in
light of other available alternatives. A continuance would
have permitted the defendant to provide testimony that would
have tended to counter the claims of the FMC doctors. With-
out the continuance, defendant was unable to do so. The util-
ity of granting a continuance in this case is therefore evident
from the record, and this factor weighs strongly in favor of
Rivera-Guerrero.

  iii.   Inconvenience

   [8] There is no evidence that the court, the parties, or any
witnesses would have been inconvenienced by a continuance.
Rivera-Guerrero’s request came at the end of a hearing at
which only the FMC doctors testified. No further witnesses
were scheduled. “Nor [was] there any indication that the . . .
delay would have necessitated the recalendaring of other mat-
ters, or otherwise have caused any significant inconvenience
to the court.” United States v. West, 828 F.2d 1468, 1470
(10th Cir. 1987).

   The only argument relating to inconvenience raised by the
government before the district court was its inability promptly
to medicate Rivera-Guerrero, render him competent, and
bring him to trial on the one count of illegal entry. It appears
that the magistrate judge adopted this unconventional theory:
“I feel that there have been significant delays . . . not only to
make this gentleman competent but to — to get him some
relief from his illness.”

  The district court’s approach ignores the defendant’s rights
and misperceives the government’s interests. The defendant’s
fundamental liberty interest is at stake. He is entitled to a full
and fair hearing before being subjected involuntarily to the
14338         UNITED STATES v. RIVERA-GUERRERO
administration of antipsychotic medications, and no such
hearing could have occurred in the absence of a continuance.
True, the government was anxious to conduct a criminal trial,
but it could not do so until after the hearing regarding invol-
untary medication had been completed. Moreover, a delay in
conducting a criminal trial of a person who is lawfully con-
fined in a mental hospital does not, without more, constitute
inconvenience to the government.

   [9] If Rivera-Guerrero had been tried and convicted after
having been granted an appropriate continuance, the fact that
he would have had to begin serving his sentence at a date later
than the one the government had hoped for, would not cause
the government any inconvenience. If the continued hearing
had resulted in a determination that Rivera-Guerrero should
not be tried, certainly no inconvenience would have been suf-
fered by anyone. Thus, this factor also weighs heavily in favor
of the defendant.

  iv.   Prejudice

   Unlike the other Flynt factors, prejudice must be shown by
the party seeking the continuance. Here the defendant has
established the requisite prejudice.

   [10] “Where the denial of a continuance prevents the intro-
duction of specific evidence, the prejudice inquiry focuses on
the significance of that evidence.” United States v. Mejia, 69
F.3d 309, 317 (9th Cir. 1995). The significance of the omitted
evidence in this case is undisputed. Because the magistrate
judge’s refusal to grant a continuance precluded Rivera-
Guerrero from having a fair opportunity to present rebuttal
evidence to the testimony of the FMC doctors, he was invol-
untarily medicated solely on the basis of the evidence offered
by the very doctors who requested his involuntary medication
in the first place. “Thus, the result of the court’s refusal to
grant a continuance ‘was to deprive [Rivera-Guerrero] of the
only testimony potentially effective to his defense.’ ” Flynt,
              UNITED STATES v. RIVERA-GUERRERO           14339
756 F.2d at 1361 (quoting United States v. Fessel, 531 F.2d
1275, 1280 (5th Cir. 1976)); see also United States v. Pope,
841 F.2d 954, 958 (9th Cir. 1988) (finding prejudice where
the denial of a continuance prevented the defendant from
introducing “the only testimony that could plausibly have
helped him.”); United States v. 2.61 Acres of Land, 791 F.2d
666, 671 (9th Cir. 1985) (finding defendant was prejudiced
because denial of a continuance prevented him from introduc-
ing any evidence in support of his position); Armant v. Mar-
quez, 772 F.2d 552 (9th Cir. 1985) (finding prejudice where
denial of a continuance effectively denied defendant the
opportunity to prepare his own defense).

   Moreover, the district court’s denial of Rivera-Guerrero’s
request for a continuance made it impossible for a medically-
informed record to be developed in the proceeding. We have
held that “the unique nature of involuntary antipsychotic med-
ication and the attendant liberty interest require that imposi-
tion of . . . [involuntary medication pursuant to Sell] occur
only on a medically-informed record.” Williams, 356 F.3d at
1056. We require that such a record be developed whenever
a Sell determination is to be made — a record that “encom-
passes an independent and timely evaluation of the [defen-
dant] by a medical professional, including attention to the
type of drugs proposed, their dosage, and the expected dura-
tion of a person’s exposure, as well as an opportunity for the
[defendant] to challenge the evaluation and offer his or her
own medical evidence in response.” Id. (emphasis added).

   By relying entirely on the medical testimony of the two
FMC doctors who initiated the request to involuntarily medi-
cate Rivera-Guerrero, and by refusing to give Rivera-
Guerrero the opportunity to present in rebuttal the evaluations
of independent medical experts as to his physical and mental
condition and as to the medical regime the government pro-
posed to use, the district court ordered involuntary medication
without the requisite complete and reliable medically-
informed record.
14340         UNITED STATES v. RIVERA-GUERRERO
   [11] In short, because the district court’s denial of defen-
dant’s request for a continuance both prevented Rivera-
Guerrero from presenting any evidence in his defense and
deprived the court of a medically-informed record upon which
the defendant’s constitutional rights could be weighed against
the government’s interest, we conclude that prejudice is
clearly established.

  v.    Summary

   [12] Rivera-Guerrero has a constitutional right not to be
involuntarily medicated in the absence of a full and fair hear-
ing. Our analysis of the four Flynt factors, as set forth supra,
plainly demonstrates that the denial of a continuance was
arbitrary and unreasonable and served to deny the defendant
due process of law. See Flynt, 756 F.2d at 1359 (reversing
denial of a continuance and stating that “appellant was enti-
tled to call psychiatric witnesses of his own choosing who,
after examining appellant, could testify as to his mental
state”). Accordingly, we reverse the district court’s order and
remand for further proceedings.

C.     On Remand

   Although we remand this case for further proceedings
because of the district court’s refusal to grant the defendant’s
request for a continuance, since the time of the defendant’s
last hearing his factual circumstances have changed dramati-
cally. The district court received a report from the FMC that
pursuant to its emergency powers, Rivera-Guerrero had been
involuntarily medicated because of alleged dangerousness.
The forced administration of medication has already occurred
and Rivera-Guerrero has already been confined in a suitable
facility for more than the permissible period of time. Accord-
ingly, on remand, conducting a Sell inquiry no longer consti-
tutes the appropriate procedure.

   Under § 4241(d), after conducting a hearing and finding
that a defendant is incompetent to stand trial, the court com-
               UNITED STATES v. RIVERA-GUERRERO            14341
mits him to a suitable facility under the custody of the Attor-
ney General for a “reasonable period of time, not to exceed
four months.” Id. This period may be extended for “an addi-
tional reasonable period of time until” the defendant is
restored to competency if the court concludes that “there is a
substantial probability that within such additional period of
time [the defendant] will attain the capacity to permit the trial
to proceed; or . . . the pending charges against him are dis-
posed of according to law; whichever is earlier.” Id. Courts
have generally construed this subsection to allow extensions
for a reasonable period of time only when “the individual is
likely to attain competency within a reasonable time.” See
e.g., United States v. Baker, 807 F.2d 1315, 1320 (6th Cir.
1986). Thereafter, the defendant may be tried, if competent,
or, if not, either civil commitment proceedings must be insti-
tuted against him under 18 U.S.C. § 4246 or he must be
released. Because of the extended period of time that has tran-
spired since Rivera-Guerrero was committed to the FMC,
almost two years, and since the FMC commenced treating
him with antipsychotic medication, approximately one year
ago, it seems clear that the statutory “reasonable period of
time” has expired and that his commitment under § 4241 must
be terminated. The only questions that remain are: what has
been the result of the FMC’s medical treatment and what are
Rivera-Guerrero’s legal rights and remedies presently?

   Upon remand, the district court is directed to order the
FMC to submit a report promptly on Rivera-Guerrero’s cur-
rent medical status, including how he has responded to the
emergency involuntary medication and whether such treat-
ment is presently continuing. If the FMC reports that Rivera-
Guerrero has been rendered competent to stand trial as a result
of its administration of the medication, and the district court
accepts that assertion, then the district court may proceed with
the criminal trial should the government still desire to do so.
If the defendant challenges the FMC report, however, the
court shall hold an appropriate hearing before determining
whether to accept the report and its findings and conclusion.
14342          UNITED STATES v. RIVERA-GUERRERO
See 18 U.S.C. § 4241(d). If, in contrast, the FMC report
asserts that, despite the passage of time and the administration
of involuntary medication, Rivera-Guerrero has not been ren-
dered competent and the district court accepts that representa-
tion, then civil commitment proceedings may be initiated
against him as provided in § 4246 (if appropriate in light of
his Mexican citizenship), deportation proceedings may be
undertaken (if such proceedings would be lawful notwith-
standing his incompetence), or he shall be unconditionally
released.

                         CONCLUSION

   The administration of involuntary medication ordinarily
constitutes a serious and substantial constitutional violation of
a defendant’s liberty interest. Although certain exceptions
exist to the general rule prohibiting involuntary medication,
the law recognizes “the importance of independent medical
decision-making” and the need for defendants to have the
“opportunity . . . to challenge [the adverse] medical evi-
dence.” Williams, 356 F.3d at 1056. Because the district
court’s denial of a continuance deprived the defendant of the
opportunity both to present such a challenge and to offer its
own independent expert witnesses, and because, as a result, a
complete and reliable medically-informed record could not be
developed, the district court’s order is reversed. On remand,
the district court shall obtain a report from the FMC and
determine defendant’s current mental status. See 18 U.S.C.
§ 4241(d). Depending on the court’s determination as to the
defendant’s competence to stand trial, the government may
prosecute him on the pending charges, deport him, if lawful
under the applicable immigration statutes, institute civil com-
mitment proceedings under § 4246, if appropriate, or release
him unconditionally.

  REVERSED AND REMANDED.
