                               In the

    United States Court of Appeals
                 For the Seventh Circuit
                     ____________________
No. 18-2279
UNITED STATES OF AMERICA,
                                                   Plaintiff-Appellee,
                                 v.

MICHAEL P. HALDORSON,
                                               Defendant-Appellant.
                     ____________________

         Appeal from the United States District Court for the
           Northern District of Illinois, Eastern Division.
         No. 1:15-cr-00623-1 — Matthew F. Kennelly, Judge.
                     ____________________

  ARGUED SEPTEMBER 26, 2019 — DECIDED OCTOBER 23, 2019
                ____________________

   Before BAUER, MANION, and ST. EVE, Circuit Judges.
    ST. EVE, Circuit Judge. Michael Haldorson is a self-pro-
claimed fireworks enthusiast. But he was also a drug dealer.
Haldorson was arrested on his way to a second controlled buy
and, along with drugs, oﬃcers found three pipe bombs in his
car. He was charged with several counts related to drugs, ex-
plosives, and a firearm. Before trial, Haldorson filed several
motions to suppress evidence, challenging his arrest, the ad-
missibility of his post-arrest statements, and the searches of
2                                                  No. 18-2279

his car, apartment bedroom, and rented storage locker. All
were denied.
    Haldorson proceeded to trial and a jury convicted him on
four counts of the seven-count indictment: Count One for dis-
tribution of cocaine, 21 U.S.C. § 841(a)(1); Count Two for pos-
session with intent to distribute cocaine, 21 U.S.C.§ 841(a)(1);
Count Three for possession of MDMA, or ecstasy, and co-
caine, 21 U.S.C. § 844(a); and Count Four for possession of an
explosive during the commission of a felony, 21 U.S.C.
§ 844(h)(2). The jury acquitted him on two additional charges
and the government dismissed another count at trial. The dis-
trict court later vacated Count Three because it was a lesser-
included oﬀense of Count Two. The district court sentenced
Haldorson to a term of imprisonment of 192 months.
    On appeal Haldorson raises three issues. First, Haldorson
argues that the district court erred in denying the motions to
suppress the evidence seized from his car and his apartment
because the oﬃcers lacked probable cause to stop and arrest
him and there were no exigent circumstances to justify the
warrantless search of his apartment bedroom. Second, he as-
serts that the jury instructions constructively amended Count
Four of the indictment, unlawfully carrying an explosive, in
violation of the Fifth Amendment by permitting the jury to
convict him on a broader basis than the indictment charged.
Third, and finally, Haldorson contends that he did not receive
a fair trial due to a multitude of alleged mistakes and errors
during the investigation and asks us to vacate his convictions.
   We conclude that probable cause supported the arrest, ex-
igent circumstances existed for the search of the bedroom, and
Haldorson had a full and fair opportunity to defend himself
No. 18-2279                                                  3

at trial. We, therefore, aﬃrm the district court’s judgment in
all respects.
              I. The Arrest and Vehicle Search
    We begin, naturally, with Haldorson’s arrest and the re-
sulting search of his vehicle.
A. Background
    Haldorson was arrested on June 23, 2015, but his case
starts a few weeks earlier. Sometime in April or May 2015,
Haldorson first came on the radar of Oﬃcer Thomas Insley
via a confidential informant. Oﬃcer Insley was, at the time, a
patrol oﬃcer with the Village of Rockdale Police Department
in Illinois. He was also assigned to a specialized narcotics
unit, the Will County Cooperative Police Assistance Team
(CPAT)—a collective of oﬃcers from local police departments
under the umbrella of the Illinois State Police—as an Inspec-
tor. (For ease we will use the title of “Oﬃcer” for Insley
throughout, although he also held the title of “Inspector” dur-
ing the relevant time period.) CPAT inspectors, in general,
conduct narcotics investigations, control informants, and go
undercover. Oﬃcer Insley was the primary CPAT investigator
for Haldorson’s case.
    Oﬃcer Insley had been working with this particular con-
fidential informant for a few months—a detail we will return
to later—when the informant told Oﬃcer Insley that he could
purchase cocaine from an individual he knew as “Mike
Jones.” The informant provided Oﬃcer Insley with a picture
of Mike Jones’s vehicle, including the license plate (that read
4                                                          No. 18-2279

“MKJNZ”), and his telephone number.1 Oﬃcer Insley ran the
license plate through a law enforcement database and learned
that it was registered to Haldorson. The vehicle information
listed on the registration also matched the photograph of Hal-
dorson’s car—a black Pontiac G8. Oﬃcer Insley then showed
the informant a picture of Haldorson, who the informant
identified as Mike Jones. At this point, Oﬃcer Insley asked the
informant to set up a deal.
    On June 1, 2015, the informant contacted Oﬃcer Insley
and told him that he could make a buy from Haldorson. Of-
ficer Insley proceeded to prepare for the controlled purchase
by providing the informant with funds to buy the narcotics,
wiring the informant with an audio transmitter and recorder
to monitor the deal, and setting up a visual surveillance team
of other CPAT oﬃcers. Before heading to the controlled buy,
Oﬃcer Insley also searched the informant and his vehicle to
make sure that he had no contraband, as is standard in these
operations.
    Oﬃcer Insley followed the confidential informant to a
Walmart parking lot in Joliet, Illinois, where he was going to
meet Haldorson, and parked about an aisle over from the in-
formant. Haldorson then arrived, parked next to the inform-
ant’s car, and the informant got out of his car and into Hal-
dorson’s car. At about that same time a customer pulled into
the lot and parked in between Oﬃcer Insley and Haldorson’s
car, obstructing Oﬃcer Insley’s view of the transaction. Not

1 This Mike Jones’s phone number was not, however, 281-330-8004. For
those unfamiliar with the reference, Mike Jones is an American rapper
whose hit single in 2005 included a verse that recited his phone number
and told listeners to “hit Mike Jones up on the low.” See Mike Jones, Back
Then, on Who Is Mike Jones? (Warner Bros. Records 2005).
No. 18-2279                                                     5

to worry, though, Oﬃcer Insley was still able to listen to the
deal in realtime from the audio transmitter.
    After the deal went down, Oﬃcer Insley observed a black
car matching the description of Haldorson’s car drive away
and relayed to the rest of the surveillance team that the con-
trolled buy was successful and to follow Haldorson’s car.
Meanwhile, Oﬃcer Insley followed the informant to a prear-
ranged location where Oﬃcer Insley retrieved the drugs from
the informant, as well as re-searched the informant and his
vehicle. The confidential informant had purchased 1.7 grams
of cocaine from Haldorson in the transaction.
    The surveillance team did not stop Haldorson that even-
ing; the oﬃcers eventually lost him when they got stopped at
a red light. But the plan was never to stop or arrest Haldorson
on June 1st because Oﬃcer Insley was just beginning his in-
vestigation into Haldorson. Further, Oﬃcer Insley testified
that if the oﬃcers arrested Haldorson immediately after the
controlled buy, it would have tipped oﬀ Haldorson that he
had been set-up by the confidential informant. Oﬃcer Insley
was using the same informant in other ongoing investigations
and did not want to burn the informant’s identity.
    From the record it appears that very little was done to ad-
vance the Haldorson investigation between the June 1st con-
trolled buy and June 23rd. There were perhaps, though it is
somewhat unclear, attempts by the confidential informant to
reach out to Haldorson to set up another controlled buy on
June 2nd and 5th, but those went nowhere.
    On June 23, 2015, the day at the center of this case, the con-
fidential informant told Oﬃcer Insley that he could arrange
another drug deal with Haldorson. The plan this time was for
6                                                            No. 18-2279

the informant to set it up but for oﬃcers to stop Haldorson on
his way to the deal and arrest him. Stopping and arresting
Haldorson before the actual drug deal would, once again, pre-
serve the confidential informant’s anonymity. Eventually
Haldorson and the informant agreed to meet in the Village of
Plainfield, Illinois, specifically at Plainfield Central High
School. Oﬃcer Insley then arranged for a Plainfield police of-
ficer in a marked car to pull Haldorson over.
    Oﬃcer Friddle of the Plainfield Police Department posi-
tioned himself near the high school and waited for Haldorson
to pass by based on a description of Haldorson’s vehicle that
CPAT oﬃcers provided: black Pontiac G8 with a White Sox
specialty license plate and red lights in the front grille of the
car (that may or may not be illuminated). According to Oﬃcer
Friddle, he soon saw a black car approaching with red lights
in the grille.2 As it got closer, he could see the White Sox spe-
cialty plates too. Oﬃcer Friddle pulled out to follow Haldor-
son’s car, activated his emergency lights, and pulled Haldor-
son over at the entrance of Plainfield Central High School. The
stop was pretextual, and Oﬃcer Friddle made up some




2 Haldorson strongly contested—and still does—the officers’ testimony
about both the presence of the red lights on his car at the June 1st con-
trolled buy (Haldorson testified and introduced receipts to demonstrate
that the lights were not installed until three days later on June 4th) and
whether the red lights were in fact illuminated when he was pulled over
on June 23rd. The district court agreed with Haldorson on this point, find-
ing that although there was a red area in the vent on top of the front hood
of the vehicle, there were not illuminated red lights. In the end, any dis-
pute regarding the red grille lights is inconsequential to the contested is-
sues in this appeal.
No. 18-2279                                                 7

excuses to buy time for CPAT oﬃcers to arrive on scene and
take over.
    Oﬃcer Mario Marzetta, a police oﬃcer with the Plainfield
Police Department who at the time was also assigned to
CPAT, arrived at the traﬃc stop shortly thereafter and ar-
rested Haldorson. Another oﬃcer transported Haldorson to
the Plainfield Police Department. Oﬃcer Marzetta then also
drove Haldorson’s vehicle to the Plainfield Police Department
and parked it in the sally port, or the garage at the station,
where he and another CPAT inspector searched it.
    The oﬃcers found numerous drugs—marijuana, cocaine,
crack cocaine, MDMA or ecstasy, prescription pills, psilocy-
bin mushrooms—fireworks, and suspected pipe bombs in
Haldorson’s car. Upon discovering the pipe bombs, the oﬃc-
ers ceased their search and called in agents from the Bureau
of Alcohol, Tobacco, Firearms and Explosives (ATF) and the
Cook County Sheriﬀ’s Police Bomb Squad. The ATF agents
and bomb technicians removed the explosives from the vehi-
cle to a safe area and rendered them safe.
    We pause the story here to address Haldorson’s challenge
to his arrest and the search of his vehicle.
B. Analysis
    Haldorson was later indicted on several federal charges.
He thereafter moved to suppress, among other evidence, the
explosives and narcotics discovered during the vehicle search
because the oﬃcers lacked probable cause to stop and arrest
him. The district court, after holding a two-day evidentiary
hearing, denied his motions to suppress. In reviewing the dis-
trict court’s denial of a motion to suppress, we review ques-
tions of law de novo and factual findings for clear error.
8                                                  No. 18-2279

United States v. Cherry, 920 F.3d 1126, 1132 (7th Cir. 2019). We
must defer to credibility determinations that the district court
made based on the testimony presented to it, absent clear er-
ror. United States v. Jones, 900 F.3d 440, 449 (7th Cir. 2018).
    1. Probable cause to arrest Haldorson
   The oﬃcers did not have a warrant to arrest Haldorson,
“but an oﬃcer may make a warrantless arrest consistent with
the Fourth Amendment if there is ‘probable cause to believe
that a crime has been committed.’” United States v. Daniels,
803 F.3d 335, 354 (7th Cir. 2015) (quoting Washington v.
Haupert, 481 F.3d 543, 547 (7th Cir. 2007)). “Police oﬃcers pos-
sess probable cause to arrest when the facts and circum-
stances within their knowledge and of which they have rea-
sonably trustworthy information are suﬃcient to warrant a
prudent person in believing that the suspect has committed
an oﬀense.” United States v. Howard, 883 F.3d 703, 707 (7th Cir.
2018) (quotations omitted). We examine “the totality of the cir-
cumstances in a common sense manner” to determine
whether probable cause exists in a given situation. United
States v. Schaafsma, 318 F.3d 718, 722 (7th Cir. 2003).
     Haldorson’s primary contention is that the information
from the controlled buy was too stale three weeks later to sup-
port probable cause for an arrest. The mere passage of time
does not necessarily dissipate the probable cause for an arrest.
It is well-established that “there is no requirement that an of-
fender be arrested the moment probable cause is established.”
United States v. Reis, 906 F.2d 284, 289 (7th Cir. 1990) (citing
Hoﬀa v. United States, 385 U.S. 293, 310 (1966)). In Reis we
found that an “overnight delay simply has no bearing on the
existence of probable cause for arrest,” id., and we see no rea-
son to treat reasonably longer delays any diﬀerent. Indeed,
No. 18-2279                                                      9

we have previously held that the defendant’s participation in
a controlled drug buy a month earlier “provided the police
with probable cause to arrest [the suspect] which was not ren-
dered stale by the passage of one month.” United States v.
Mitchell, 523 F. App’x 411, 414 (7th Cir. 2013) (per curiam).
Our sister circuits also agree that the passage of time alone
does not render probable cause to arrest stale. See, e.g., United
States v. Azor, 881 F.3d 1, 9 (1st Cir. 2017) (“Our case law
makes clear that law enforcement is not required to arrest a
suspect immediately upon development of probable cause.”);
United States v. Clark, 647 F. App’x 419, 422 (5th Cir. 2016) (per
curiam) (“[P]robable cause existed to arrest [the defendant]
because the earlier tip from the confidential informant and the
controlled purchase [four to six days earlier] provided [the
police] with facts that would support a reasonable person’s
belief that an oﬀense had been committed and that the indi-
vidual arrested was the guilty party.” (cleaned up)); United
States v. Winchenbach, 197 F.3d 548, 554 (1st Cir. 1999)
(“[W]hen probable cause exists, the timing of an arrest is a
matter that the Constitution almost invariably leaves to police
discretion.”); United States v. Bizier, 111 F.3d 214, 220 (1st Cir.
1997) (holding that “the period of time between the controlled
buys [—four days after the second controlled buy and less
than two weeks after the first controlled buy—] and the arrest
was not so long here as to render the probable cause stale in
any meaningful temporal sense”); cf. Guadarrama v. United
States, No. 16-6218, 2017 WL 3391683, at *2 (6th Cir. Feb. 13,
2017) (unpublished order) (stating that “[r]easonable jurists
could not debate th[e] conclusion” that “while information
used to obtain a search warrant may go stale, the same is not
true for information underlying an arrest warrant”).
10                                                 No. 18-2279

    Our facts are nearly identical to those that the Tenth Cir-
cuit confronted in United States v. Hinson, 585 F.3d 1328 (10th
Cir. 2009). There, the police arranged for a controlled buy be-
tween an informant and the defendant at an auto parts store.
Police surveilled the informant while he drove to the location,
got into the defendant’s car, and negotiated the purchase of
methamphetamine. Id. at 1331. The police did not immedi-
ately arrest the defendant, “[a]pparently hoping to investigate
further.” Id. About a month later, the police sought to have the
informant conduct another controlled buy but the informant
refused (even though a few days earlier he told the police he
could set up another deal). Unable to convince the informant
to cooperate, the police resolved to arrest the defendant. In-
stead of obtaining an arrest warrant, they decided to simply
follow his car until he committed a traﬃc violation and then
stop and arrest him—which they did. Id. at 1331–32. The
Tenth Circuit held that the police oﬃcers had probable cause
to arrest the defendant “based on the controlled buy they wit-
nessed a month before his arrest.” Id. at 1334. “[T]he passage
of time did not make that information stale or otherwise de-
stroy the oﬃcers’ probable cause.” Id.
    There was probable cause to arrest Haldorson on June 23,
2015, based on the June 1, 2015, controlled buy. The facts over-
whelmingly support this conclusion. The confidential inform-
ant first provided Oﬃcer Insley with Haldorson’s phone
number and a picture of his black Pontiac G8, including the
license plate. Oﬃcer Insley was able to run the license plate
through a law enforcement database and trace the car’s regis-
tration to Haldorson. The informant then positively identified
a photograph of Haldorson as his drug supplier. But the prob-
able cause for the arrest was not merely based on a “tip” from
No. 18-2279                                                               11

a confidential informant3—that was just the beginning. The
oﬃcers then set up a controlled buy. Multiple oﬃcers were
surveilling the deal and observed Haldorson’s car drive into
the parking lot at the prearranged location, park next to the
confidential informant, and the confidential informant get
into the passenger seat of Haldorson’s car. Although no oﬃc-
ers witnessed the actual transaction, Oﬃcer Insley listened to
the entire interaction in realtime via the informant’s hidden
wire. Oﬃcer Insley also searched the confidential informant
and his car both before and after the controlled buy; the only
drugs he had were the 1.7 grams of cocaine purchased from
Haldorson during the controlled buy. On this last point, criti-
cally, the district court found Oﬃcer Insley’s testimony cred-
ible, and we certainly cannot say that that finding was clearly
erroneous. The passage of three weeks did not render the in-
formation from the controlled buy stale.
   It is the rare case where “staleness” will be relevant to the
legality of a warrantless arrest.4 When there is a reasonable


3 Haldorson makes repeated references to initially undisclosed infor-
mation regarding the confidential informant’s history—including how he
came to be an informant, his motivation (was he working for money or
working off his own case), and the fact that he was arrested on an unre-
lated incident approximately ten days before the controlled buy. If Officer
Insley had relied on an affidavit from the confidential informant in an ap-
plication for a search warrant, the nondisclosure of such credibility infor-
mation would be relevant to the question of probable cause. United States
v. Musgraves, 831 F.3d 454, 460 (7th Cir. 2016). But this case does not in-
volve simply relying on information from a confidential informant in an
affidavit.
4 Conversely, the concept of staleness is generally a “highly relevant” fac-
tor in applications for search warrants because, unlike arrests, the focus is
on whether “evidence of a crime will be found in a particular place” and
12                                                            No. 18-2279

belief that someone has committed a crime, time by itself does
not make the existence of that fact any less probable. Cer-
tainly, “[g]ood police practice often requires postponing an
arrest, even after probable cause has been established, in or-
der to place the suspect under surveillance or otherwise de-
velop further evidence necessary to prove guilt to a jury.”
United States v. Watson, 423 U.S. 411, 431 (1976) (Powell, J., con-
curring). This is not to say that the passage of time can never
dissipate probable cause to arrest. There could be circum-
stances in which the subsequent investigation turns up new
facts or evidence that disprove or discredit the original infor-
mation. Cf. id. at 432 n.5. We simply do not have those facts
here and thus do not need to address if or when probable
cause to arrest may become stale.
   The information provided by the confidential informant
and the June 1st controlled buy provided probable cause to
arrest Haldorson on June 23, 2015.
     2. Vehicle search
    Haldorson makes passing references to the search of his
car but does not meaningfully contest the district court’s rul-
ing that the evidence would have been inevitably discovered.
In any event, Haldorson’s challenge fails. The inevitable dis-
covery doctrine provides that illegally obtained evidence will
not be excluded if the government “can establish by a prepon-
derance of the evidence that the information ultimately or in-
evitably would have been discovered by lawful means.” Nix
v. Williams, 467 U.S. 431, 444 (1984). Once Haldorson was law-
fully arrested, his “car could not be left unattended

often involve a search for perishable or transportable objects, like drugs or
guns. United States v. Bradford, 905 F.3d 497, 503–04 (7th Cir. 2018).
No. 18-2279                                                     13

indefinitely” at the entrance of a public high school. United
States v. Simms, 626 F.3d 966, 971 (7th Cir. 2010); see also United
States v. Stotler, 591 F.3d 935, 940 (7th Cir. 2010) (“[O]bviously,
the arresting oﬃcers would not have allowed the truck to just
sit on the street after [the arrestee] was carted away.”). The
police oﬃcers would have towed his vehicle to the police sta-
tion and conducted an inventory search of the vehicle per es-
tablished Plainfield Police Department procedures. “The
drugs [and explosives], therefore, inevitably would have been
discovered during an inventory search.” Cherry, 920 F.3d
at 1140.
   We aﬃrm the denial of Haldorson’s motion to suppress
the evidence seized from his vehicle.
                   II. The Apartment Search
    We pick up the facts where we left oﬀ, with Haldorson at
the Plainfield Police Department and the oﬃcers’ discovery of
drugs and explosives in his car.
A. Background
    Oﬃcers interviewed Haldorson multiple times the even-
ing of his arrest and carrying over into the early morning
hours of the next day, June 24, 2015. The oﬃcers read Haldor-
son his Miranda rights on at least two separate occasions over
the course of the interviews. After finding pipe bombs in Hal-
dorson’s car, the CPAT oﬃcers and ATF agents were particu-
larly concerned that Haldorson had stored additional explo-
sive materials at his residence. When oﬃcers initially asked
him for his current address, Haldorson told the oﬃcers that
he was homeless. Oﬃcer Insley believed that Haldorson lived
in downtown Plainfield, and specifically on or around Lock-
port Street, based on information he had previously gathered
14                                                No. 18-2279

and because oﬃcers had seen Haldorson’s car parked on that
street during the investigation. Haldorson told them that he
was dating a woman over there but denied living in the
downtown Plainfield area. He eventually claimed that he
lived in Joliet at his parents’ house and provided an address.
Asked if there were any additional explosives at that home,
Haldorson responded that there could be.
    With this information, CPAT oﬃcers and ATF agents left
the police station and went to the Joliet address. They arrived
at Haldorson’s parents’ home at approximately 2:45 a.m. on
June 24, 2015. Haldorson’s parents gave the officers consent
to search Haldorson’s room, which revealed narcotics-related
items but no explosives. After speaking with Haldorson’s fa-
ther, the officers learned that Haldorson did in fact reside at
an apartment in downtown Plainfield, on Lockport Street. His
father did not know the exact address but gave a general de-
scription of the area and Haldorson’s apartment. Officers im-
mediately went to that location.
   Now on Lockport Street, at approximately four o’clock in
the morning, the officers—without a precise address—pro-
ceeded to knock on the street-level doors of the buildings (the
buildings were retail business on the first floor and apart-
ments on the second), and eventually located and gained ac-
cess to Haldorson’s apartment building.
   Once inside the apartment building, the officers knocked
on Haldorson’s unit’s front door. A woman answered the
door (and gave the same name as the name of the woman Hal-
dorson said he was dating), who told the officers that Haldor-
son lived there. She gave the officers consent to enter and
search the common areas of the apartment, and even signed a
written consent form. Haldorson had a separate bedroom in
No. 18-2279                                                 15

the apartment, which was locked. The officers used Haldor-
son’s keys that were taken during his arrest to open his bed-
room door. According to the Plainfield police sergeant on the
scene, the officers made the decision to enter Haldorson’s
locked bedroom to search for explosives because they were
concerned for the safety of his roommate and the other resi-
dents and businesses on Lockport Street if there were, indeed,
explosives in the bedroom. The officers did not have a search
warrant at the time.
    In Haldorson’s bedroom officers founds fireworks and ex-
plosives. They removed the explosives from the bedroom and
secured them in a steel box on ATF trucks. At that moment
the officers did not seize anything else from Haldorson’s bed-
room except for the explosives. In fact, the officers testified
that they only conducted a “plain view” search for explosives
and then stopped their search. Instead, the officers then ap-
plied for and received a search warrant for the apartment. The
second search did not produce any additional explosives, but
officers did seize narcotics-related items and two laptop com-
puters.
    Later that same day, armed with the search warrant, offic-
ers also searched two storage lockers that belonged to Haldor-
son. They did not find any explosives or narcotics in one of
the lockers, but seized PVC pipe, multiple low explosive pow-
der canisters, fireworks, and a handgun and ammunition
from the second locker.
    We break from recounting the facts again to tackle the le-
gality of the bedroom search.
16                                                   No. 18-2279

B. Analysis
    When the police officers entered Haldorson’s bedroom
and searched it for explosives, they did not have a search war-
rant or consent. “Warrantless searches and seizures within a
home are considered presumptively unreasonable and a vio-
lation of the Fourth Amendment.” United States v. Huddleston,
593 F.3d 596, 600 (7th Cir. 2010). There are, however, “certain
narrowly proscribed exceptions.” United States v. Bell,
500 F.3d 609, 612 (7th Cir. 2007). One such exception is where
“exigent circumstances require officers to ‘step in to prevent
serious injury and restore order.’” Huddleston, 593 F.3d at 600
(quoting Bell, 500 F.3d at 612). Under the exigent circum-
stances exception, “a warrantless entry into a dwelling may
be lawful when there is a pressing need for the police to enter
but no time for them to secure a warrant.” Sutterfield v. City of
Milwaukee, 751 F.3d 542, 557 (7th Cir. 2014). The test is
whether “an officer had an objectively ‘reasonable belief that
there was a compelling need to act and no time to obtain a
warrant.’” Huddleston, 593 F.3d at 600 (quoting Bell, 500 F.3d
at 613). The existence of exigent circumstances is a mixed
question of fact and law that we review de novo. Id. We still
review the district court’s factual findings for clear error.
United States v. Delgado, 701 F.3d 1161, 1164 (7th Cir. 2012).
    The exigent circumstances exception is “frequently in-
voked in cases involving explosives.” United States v. Witzlib,
796 F.3d 799, 802 (7th Cir. 2015) (collecting cases and citing,
for example, United States v. Infante, 701 F.3d 386, 393–94 (1st
Cir. 2012); Armijo ex rel. Armijo Sanchez v. Peterson, 601 F.3d
1065, 1071–73 (10th Cir. 2010); United States v. Lindsey,
877 F.2d 777, 781–82 (9th Cir. 1989); United States v. Al–Az-
zawy, 784 F.2d 890, 894 (9th Cir. 1985)). Explosives are, by their
No. 18-2279                                                17

very nature, inherently dangerous. Homemade explosive de-
vices even more so because the persons manufacturing them
often lack the needed technical knowledge and skills. There-
fore, even though Haldorson enjoyed a strong expectation of
privacy in his locked bedroom, that expectation must be bal-
anced against the need to protect the public from serious
harm where explosive materials may be present in a residen-
tial complex with close neighbors. United States v. Boettger,
71 F.3d 1410, 1414 (8th Cir. 1995) (“[Privacy] expectations
must be lowered where a resident admits working with ex-
plosive materials in an apartment complex with close neigh-
bors.”); see Michigan v. Cliﬀord, 464 U.S. 287, 297 n.8 (1984)
(careful “not to suggest that individual expectations of pri-
vacy may prevail over interests of public safety”).
    The following objective facts, found by the district court
and not clearly erroneous, were known to the oﬃcers before
they entered into Haldorson’s bedroom: Explosive materials,
including pipe bombs, were found in Haldorson’s car; pipe
bombs, according to the Cook County Sheriﬀ’s Police Bomb
Squad and ATF agents, are very volatile and dangerous; Hal-
dorson admitted that more explosives could be at his resi-
dence; Haldorson falsely told oﬃcers that he lived at his par-
ents’ house, and a search of that house uncovered no explo-
sives; and Haldorson actually resided at an apartment in
downtown Plainfield, which was surrounded by residential
neighbors and businesses. Moreover, the district court found
that an ATF agent credibly testified that there was a “legiti-
mate concern” that other homemade explosives were “poten-
tially unstable and therefore dangerous to others.” Based on
these facts, the oﬃcers reasonably believed that there was a
justifiable and urgent need to act to prevent serious harm.
18                                                            No. 18-2279

   Because of the acute concern and the hour at which the
oﬃcers and agents were urgently proceeding, around three
and four o’clock in the morning, there was no time to obtain
a warrant.
    Haldorson relies on the fact that the oﬃcers and agents
only conducted a plain view search for explosives in his bed-
room to question their belief that the explosives posed an im-
mediate threat. But, as the district court noted, law enforce-
ment oﬃcers took additional steps consistent with their belief
that the explosives posed an immediate threat, including
clearing Haldorson’s girlfriend from the apartment. Further,
contrary to Haldorson’s contention that their “true aim and
intent” was to conduct a warrantless search, the fact that the
oﬃcers only did a plain view search shows that the expressed
concern was not simply pretext for searching for and gather-
ing evidence of criminal activity. See Cliﬀord, 464 U.S. at 292.
The search did not exceed the scope of the exigency. See
United States v. Salava, 978 F.2d 320, 325 (7th Cir. 1992) (“The
ensuing search … was appropriately limited to the [exigent]
circumstances that justified it.”).
    Haldorson also emphasizes that he was in custody and
therefore “any alleged explosive materials were stable and in-
ert.” The opposite is true—homemade pipe bombs, and other
improvised explosive devices, are unstable.5 An ATF agent,

5 It is for this same reason that we find unpersuasive Haldorson’s reliance

on United States v. Yengel, 711 F.3d 392 (4th Cir. 2013), which involved a
warrantless search based on the possible threat of a grenade inside a
home. Upon learning of the possible existence of a grenade, however, the
officer did not call for the assistance of explosive experts, or even “remove
the sleeping child from the room located directly next to the room where
the ‘grenade’ was allegedly stored.” Id. at 395. The officer’s “own actions
belie[d]” the argument that there were exigent circumstances. Id. at 398.
No. 18-2279                                                                19

who has experience and expertise with explosives, credibly
testified to this below.6 In short, the oﬃcers reasonably be-
lieved that the homemade pipe bombs posed an immediate
threat to public safety.
    Given the facts and information known at the time of the
search, “from the perspective of the oﬃcers at the scene,”
Huddleston, 593 F.3d at 600, there was a legitimate concern
that other homemade explosive devices were in Haldorson’s
bedroom that were potentially unstable and therefore danger-
ous to others. The warrantless search fell within the exigent
circumstances exception to the Fourth Amendment’s warrant
requirement.
       III. Constructive Amendment to the Indictment
   Back to the facts, and with the pretrial motions and evi-
dentiary issues on appeal taken care of, we turn to Haldor-
son’s objections to the jury instructions.
   Haldorson challenges the instructions to the jury on Count
Four as a constructive amendment to the indictment. Count


The officer acted with no level of urgency. Importantly, and distinct from
our circumstances, the Fourth Circuit noted that there was “no indication
that there might be other, more unstable explosives, inside as well.” Id. (em-
phasis added).
6 See also Fact Sheet–Illegal Explosive Devices, Bureau of Alcohol, Tobacco,
Firearms and Explosives (May 2019), https://www.atf.gov/resource-cen-
ter/fact-sheet/fact-sheet-illegal-explosive-devices (“Illegal explosive de-
vices … are typically extremely sensitive to heat, shock, electrostatic dis-
charge and friction that may initiate, unexpectedly causing serious injury
or death. The risks associated with these devices are further compounded
because the persons manufacturing, transporting and using these devices
often do not have the knowledge, skills and experience required for such
activities.”).
20                                                    No. 18-2279

Four of the indictment charged, in pertinent part, that Haldor-
son “unlawfully carried an explosive, namely, smokeless
powder, during the commission of a felony … .” Because the
indictment charged him with carrying a specific object—
smokeless powder—the jury could only convict if it found be-
yond a reasonable doubt that Haldorson carried smokeless
powder, not just any explosive material. Haldorson argues
that the jury instructions on Count Four unconstitutionally
broadened the bases of conviction by permitting the jury to
convict if they found he carried any explosive. This is a ques-
tion of law that we review de novo. United States v. Mitov,
460 F.3d 901, 906 (7th Cir. 2006).
     The Fifth Amendment provides that “[n]o person shall be
held to answer for a capital, or otherwise infamous crime, un-
less on a presentment or indictment of a Grand Jury.” U.S.
Const. amend. V. Only the grand jury can amend the indict-
ment to broaden it. Stirone v. United States, 361 U.S. 212, 216
(1960); United States v. Pierson, 925 F.3d 913, 919 (7th Cir. 2019).
“This rule both enforces the Fifth Amendment and helps to
ensure that a defendant is given reasonable notice of the alle-
gations against him so that he may best prepare a defense.”
Pierson, 925 F.3d at 919. A constructive amendment “occurs
when either the government (usually during its presentation
of evidence and/or its argument), the court (usually through
its instructions to the jury), or both, broadens the possible ba-
ses for conviction beyond those presented by the grand jury.”
United States v. Cusimano, 148 F.3d 824, 829 (7th Cir. 1998).
   The statute under which Haldorson was charged,
18 U.S.C. § 844(h)(2), does not require a specific type of explo-
sive as an element—it criminalizes “carr[ying] an explosive
during the commission of any felony” (subject only to the
No. 18-2279                                                 21

definition of “explosive” in 18 U.S.C. § 841(d)). But the gov-
ernment narrowed the charge against Haldorson by including
the specific language “namely, smokeless powder” in the in-
dictment. “Specific language in an indictment that provides
detail beyond the general elements of the crime makes the
specified detail essential to the charged crime and must,
therefore, be proven beyond a reasonable doubt.” Pierson,
925 F.3d at 920.
   The district court instructed the jury on Count Four as fol-
lows:
      In order for you to find the defendant guilty of
      the charge of carrying an explosive during the
      commission of a felony as alleged in Count
      Four, the government must prove both of the
      following elements beyond a reasonable doubt:
      …
      2. The defendant knowingly carried an explo-
      sive, namely, smokeless powder, during the
      commission of that crime [in element 1 of the in-
      struction] … .
The jury instruction also included the specific language
“namely, smokeless powder.” It was added during the final
jury instructions conference at the insistence of Haldorson.
   The jury instruction for Count Four and Count Four of the
indictment both included the identical specific language re-
garding smokeless powder. The instruction thus required the
jury to find, beyond a reasonable doubt, that Haldorson
knowingly carried an explosive and that that explosive was
smokeless powder, just as Count Four charged.
22                                                  No. 18-2279

   This is unlike our decisions in Pierson and Leichtnam,
which Haldorson attempts to rely on for support. In both
cases, the indictment narrowed the bases of conviction by
naming a particular firearm that the defendant was charged
with. Pierson, 925 F.3d at 920; United States v. Leichtnam,
948 F.2d 370, 374 (7th Cir. 1991). And in both cases, the corre-
sponding jury instruction failed to specify the exact gun
charged, while at the same time evidence of additional non-
indicted guns were presented at trial. “[T]his combination of
the evidence and untailored jury instructions added up to a
constructive amendment.” Pierson, 925 F.3d at 920. This is not
our case. The jury instruction was tailored to the specifics of
the indictment and did not permit the jury to convict Haldor-
son based on non-indicted explosives. No constructive
amendment of the indictment occurred.
    Finally, Haldorson makes a passing suggestion that there
is “another independent problem” with the jury instructions
on Count Four: the instruction contained “vastly more lan-
guage” than the elements of the offense. According to Haldor-
son, the language was unnecessary, irrelevant, and suggestive
of the facts in evidence.
    On a challenge to a jury instruction, our review is twofold.
First, “we review de novo whether the jury instructions accu-
rately summarize the law, but give the district court substan-
tial discretion to formulate the instructions provided that the
instructions represent a complete and correct statement of the
law.” United States v. Bonin, 932 F.3d 523, 537–38 (7th Cir.
2019). If the instruction is legally accurate, in the second step
we then “review the district court’s phrasing of the instruc-
tions for abuse of discretion.” Id.
No. 18-2279                                                   23

   The district court further instructed the jury that:
       The explosive does not have to be related to the
       other crime. A person carries an explosive if he
       knowingly transports it on his person or in a ve-
       hicle or container. A person may carry an explo-
       sive even if it is not immediately accessible be-
       cause it is in another area of a vehicle. The term
       “during” means at any point within the conduct
       charged in Count Two and Count Three.
The first and fourth sentences accurately summarize the ap-
plicable law and Supreme Court precedent. In Ressam, the
Court held that 18 U.S.C. § 844(h)(2) does not require a rela-
tionship between the explosive carried and the underlying fel-
ony, and that “during” denotes a straightforward temporal
link. United States v. Ressam, 553 U.S. 272, 274 (2008).
    The second and third sentences above are strictly defini-
tional. There is no suggestion that they are incorrect, misstate-
ments, or could not have alternatively been included in the
separate “Definitions” instruction that the court provided to
the jurors. Because the instruction on Count Four accurately
stated the law, it was not an abuse of discretion to provide the
additional language to the jury.
       IV. Mistakes During the Police Investigation
   As a last resort, Haldorson asks this court to vacate his
convictions because the convictions are “plagued by con-
cealed material information, false and misleading reports,
perjured testimony, an unlawful recording, scant evidence,
contaminated evidence, [and] evidence disappearing from
the evidence vault.” The crux of his argument on appeal is
that the cumulative eﬀects of the perceived mistakes and
24                                                            No. 18-2279

violations during the investigation deprived him of his Fifth
and Sixth Amendment rights to a fair trial.7
    The problem for Haldorson is that all of the asserted errors
he claims infected his trial were known to him before trial and
he made extensive use of them at trial on cross-examination.
Each and every misstep that the oﬃcers and the federal agents
allegedly made along the way came out at trial. In fact, in clos-
ing arguments, Haldorson essentially argued to the jury what
he now argues on appeal.
    Much of Haldorson’s argument can be disposed of with
that, but we conclude with a brief comment on one of the spe-
cific allegations concerning irregularities with Oﬃcer Insley’s
handling of the confidential informant. The primary issue is
that Oﬃcer Insley did not disclose the informant’s arrest that
occurred ten days before the controlled buy to his police su-
pervisors or to the prosecutors. A confidential informant’s
personal and criminal history is material information and is
often critical to diﬀerent stages of an investigation or prose-
cution. When the police seek a search warrant based in part
on an informant, for example, the omission of adverse infor-
mation may impair the neutral role of the magistrate deciding
whether to issue the warrant. E.g., United States v. Glover,
755 F.3d 811, 817 (7th Cir. 2014). Similarly, the government


7 Importantly, although his argument is framed similarly, Haldorson’s ar-

gument is not one of cumulative error because he does not allege that any
errors were committed in the course of the trial. See United States v. Mar-
chan, 935 F.3d 540, 549 (7th Cir. 2019) (“To establish cumulative error a
defendant must show that (1) at least two errors were committed in the
course of the trial; [and] (2) considered together along with the entire rec-
ord, the multiple errors so infected the jury’s deliberation that they denied
the petitioner a fundamentally fair trial.”).
No. 18-2279                                                   25

would have to disclose that same adverse information to the
defense as exculpatory material under Brady v. Maryland, 373
U.S. 83 (1963), and Giglio v. United States, 405 U.S. 150 (1972).
In this particular case, Oﬃcer Insley’s lack of disclosure did
not taint any later stages of the investigation or prosecution.
No warrants, evidence, or testimony relied on the informant’s
credibility.
    Mistakes were made during the police investigation of
Haldorson. The government readily concedes as much. But
those mistakes did not deprive Haldorson of his constitu-
tional rights. Haldorson had a full and complete opportunity
to defend himself against the government’s charges and re-
ceived a fair trial.
                                                   AFFIRMED.
