In the
United States Court of Appeals
For the Seventh Circuit
____________________
No. 24-1206
MARK PETERSEN,
Plaintiff-Appellant,
v.
STEFANIE PEDERSEN,
Defendant-Appellee.
____________________
Appeal from the United States District Court for the
Eastern District of Wisconsin.
No. 1:22-cv-00684 — William C. Griesbach, Judge.
____________________
ARGUED SEPTEMBER 25, 2024 — DECIDED JUNE 10, 2025
____________________
Before SCUDDER, KIRSCH, and MALDONADO, Circuit Judges.
MALDONADO, Circuit Judge. Mark Petersen sued Deputy
Stefanie Pedersen under 42 U.S.C. § 1983, alleging that she
falsely arrested him for drunk driving and unlawfully drew
his blood. The district court granted Deputy Pedersen’s mo-
tion for summary judgment on both claims and also granted
her qualified immunity. We affirm, concluding that probable
cause supported the arrest, the blood draw was taken
2 No. 24-1206
pursuant to a valid search warrant, and, regardless, that Dep-
uty Pedersen is entitled to qualified immunity.
BACKGROUND
I. Facts
The following facts are undisputed by the parties and cor-
roborated by video footage. At the summary judgment stage,
we state these facts as favorably to Mr. Petersen as the record
permits. Smith v. Crounse Corp., 72 F.4th 799, 804 (7th Cir.
2023).
On the evening of December 27, 2018, Deputy Stephanie
Pedersen of the Winnebago County Sherriff’s Office was dis-
patched to a reported car crash outside a home in rural Wis-
consin. An unidentified caller reported hearing a crash, look-
ing outside, and seeing a car immobilized in a residential
driveway. While the caller neither witnessed the crash nor
saw who was driving the car, they observed a man loitering
near the car.
Deputy Pedersen arrived at the scene approximately fif-
teen minutes after the 911 call was placed. She immediately
observed tire marks running through the residence’s front
yard and broken tree branches scattered on the ground. As
she pulled into the driveway, her squad car stopped in front
of the disabled car, where Mr. Petersen was hunched over, at-
tempting to change its front-passenger tire. Five adults, either
residents or guests at the home, stood nearby as Mr. Petersen,
unsteady on his feet, nearly toppled over while torquing the
lug nuts with a crowbar.
Deputy Pedersen ran the car’s license plates and learned
that it was registered to Mark Petersen. Mr. Petersen was no
stranger to Deputy Pedersen or the local sheriff’s office.
No. 24-1206 3
Generally, he had established a reputation for being uncoop-
erative during law enforcement encounters. He had three
prior charges for operating a vehicle while intoxicated (OWI),
see WIS. STAT. § 346.63(1), which triggered a .002 g/100 mL
blood alcohol concentration (BAC) restriction on his driver’s
license. Deputy Pedersen had arrested Mr. Petersen on a pre-
vious occasion and recognized him as the man changing the
car’s tire. Additionally, dispatch informed her that Mr. Pe-
tersen’s driver’s license and license plates were currently sus-
pended.
After receiving this information, Deputy Pedersen
stepped out of her car and approached Mr. Petersen. Immedi-
ately, he began wandering away from her. He first walked to-
wards the back of his car, creating a buffer between him and
Deputy Pedersen, and then suddenly rushed away from the
car and through the residence’s front yard, ignoring her re-
peated commands that he “Stop!” He did not make it far,
however, because Deputy Pedersen quickly grabbed him by
the arm.
Once caught, Mr. Petersen acknowledged Deputy Peder-
sen’s presence for the first time, asking in a noticeably slurred
voice, “you talkin’ to me?” Deputy Pedersen confirmed that
she was and asked him what happened that night. He re-
sponded, “I was just coming here to get my motor vehicle,
what’s going on with you?” She repeated her question, and
he answered, “I said, my daughter, she’s called me out here.
Came out here to fix the tire. You guys know anything about
that or are you all good?” After answering, he attempted to
escape Deputy Pedersen’s grip, but she took hold of his arm
again and repeated her warning that he stop resisting.
4 No. 24-1206
Deputy Pedersen continued her questioning, asking how
his car ended up in the driveway, to which Mr. Petersen
slowly answered, “My … daughter’s … down here.” Deputy
Pedersen probed where his daughter was (since she was not
on the scene), and he saucily countered, “I don’t know,
where’s your daughter?” When Deputy Pedersen pressed
him on who was driving his car that night, he again blamed
his daughter, “Trisha,” and explained, “I don’t drive any-
thing. I took … the front road, like she’ll drive me right here
… like I don't drive. I don’t drive anymore.” Deputy Pedersen
then turned to the bystanders and asked if Mr. Petersen was
the only person they saw near the car, and they responded
affirmatively. At this point, Deputy Pedersen handcuffed and
formally arrested Mr. Petersen for drunk driving. Other offic-
ers had arrived by now and assisted in the arrest.
Several factors led to Deputy Pedersen’s belief that she
had probable cause to arrest Mr. Petersen for OWI. First, the
tire tracks through the grass, downed branches, and flat tire
suggested that the car had been pulled off the road in an er-
ratic manner. Second, upon making contact with Mr. Pe-
tersen, she detected a strong odor of intoxicants and noticed
his eyes were glassy and bloodshot. She also observed his
slurred speech and lack of balance, swaying from side-to-side
as he stood. Based on her specialized drug recognition train-
ing, these characteristics were consistent with intoxication.
Third, based on her past familiarity with Mr. Petersen, she
knew that he had been estranged from his daughter for sev-
eral years, and thus was dubious of his version of events. She
also knew that he had several previous OWI charges and that
his license was currently suspended. Finally, the bystanders’
confirmation that he was the only person they saw near the
No. 24-1206 5
vehicle gave her enough information, in her view, to make the
arrest.
After handcuffing him, Deputy Pedersen conducted a
search incident to arrest. In his coat pockets, she found car
keys, lug nuts, and a container holding a leafy green sub-
stance that she suspected was marijuana. She and the sup-
porting officers then placed Mr. Petersen in the back of the
squad car and secured his seatbelt—overcoming his contin-
ued resistance and disregarding his provocations, including
his quip: “Buckle it up, buttercup!” With Mr. Petersen re-
strained in the backseat, Deputy Pedersen continued her in-
vestigation, including driving to the local hospital to conduct
a BAC test.
While en route to the hospital, despite the bystanders’
statements that they saw no second person at the scene, Dep-
uty Pedersen attempted to corroborate Mr. Petersen’s account
that his daughter was driving his car that evening. She asked
him for his daughter’s phone number, but he did not respond
to her request. Persistent in her investigation, Deputy Peder-
sen then decided to call Mr. Petersen’s mother, whom she had
met during a prior encounter with him. Deputy Pedersen ex-
plained the situation to his mother and asked if she knew
whether his daughter had driven his car. His mother was un-
certain but said that it would be surprising, given the es-
trangement between him and his daughter. She also con-
firmed that his daughter’s name was Aubrey, not Trisha, as
Mr. Petersen had previously stated.
Approximately twenty minutes after leaving the crash
site, they arrived at the hospital and parked outside. Deputy
Pedersen asked Mr. Petersen if he would voluntarily consent
to a blood draw, but he refused to answer. So she contacted
6 No. 24-1206
the on-call judge, Judge Karen L. Seifert, to request a search
warrant for the BAC test. Under oath, Deputy Pedersen orally
outlined the circumstances leading to Mr. Petersen’s arrest,
and, after a series of questions, Judge Seifert authorized the
warrant. Equipped with a search warrant, Deputy Pedersen
had hospital staff draw Mr. Petersen’s blood, which showed
he had a BAC of 0.213 g/100 mL—well above the legal limit of
.08 g/100mL and his lower-restricted limit of .002 g/100mL.
II. Procedural History
The next day Mr. Petersen was criminally charged with
one count of OWI – 4th Offense in the Circuit Court of Winne-
bago County. See State v. Mark Petersen, Case No. 18-CF-847
(Winnebago Cnty., Wis.). In those state court proceedings,
Mr. Petersen moved to suppress the evidence from his BAC
test, arguing that Deputy Pedersen lacked probable cause to
arrest him for OWI. After a hearing and supplemental brief-
ing, the state trial court granted Mr. Petersen’s motion to sup-
press, finding that Deputy Pedersen lacked probable cause to
arrest. 1 As a result, the State voluntarily dismissed its case
against Mr. Petersen.
Then Mr. Petersen flipped the script. In June 2022, he sued
the officers involved in his arrest and several governmental
entities under 42 U.S.C. § 1983, alleging that they violated his
Fourth Amendment rights. At the motion-to-dismiss stage,
the district court reduced the case to two Fourth Amendment
claims, both against Deputy Pedersen: one for false arrest and
1 The summary judgment record does not reveal the state trial court’s
rationale for concluding that Deputy Pedersen lacked probable cause.
No. 24-1206 7
one for an unreasonable search based on the nonconsensual
blood draw.
After discovery, Deputy Pedersen moved for summary
judgment, arguing that (1) she had probable cause to arrest
Mr. Petersen for OWI, (2) the blood draw was made pursuant
to a valid search warrant, and (3) she was qualifiedly immune
from Mr. Petersen’s claims. The district court granted her mo-
tion in its entirety. Mr. Petersen now appeals, asserting that
probable cause was lacking throughout the encounter be-
cause no one personally observed him driving.
DISCUSSION
We review the district court’s summary judgment ruling
de novo and draw all reasonable factual inferences in Mr. Pe-
tersen’s favor. Gaddis v. DeMattei, 30 F.4th 625, 630 (7th Cir.
2022).
I. The Arrest
A § 1983 claim for false arrest cannot succeed if the officer
had probable cause to make the arrest. Mwangangi v. Nielsen,
48 F.4th 816, 825 (7th Cir. 2022). Probable cause to arrest exists
“when a reasonable officer with all the knowledge of the on-
scene officers would have believed that the suspect commit-
ted an offense defined by state law.” Jump v. Village of Shore-
wood, 42 F.4th 782, 789 (7th Cir. 2022). “Probable cause does
not require certainty”; instead, “it is a fluid concept that relies
on the common-sense judgment of the officers based on the
totality of the circumstances.” Hart v. Mannina, 798 F.3d 578,
587 (7th Cir. 2015) (cleaned up).
In a typical false-arrest case, the issue of probable cause
will be decided by a jury after surviving summary judgment.
Abbott v. Sangamon County, 705 F.3d 706, 714 (7th Cir. 2013)
8 No. 24-1206
(“Usually in a § 1983 false-arrest case the jury determines
whether the arrest was supported by probable cause ….”);
Rooni v. Biser,
742 F.3d 737, 740 (7th Cir. 2014) (“The probable
cause determination must be made by a jury if there is room
for a difference of opinion concerning the facts or the reason-
able inferences to be drawn from them.”). “[B]ut if the under-
lying facts are undisputed, the court can make [the probable
cause] decision on summary judgment.” Abbott,
705 F.3d at
714. This is the atypical case in which the parties agree on the
facts but dispute whether probable cause exists, making sum-
mary judgment (one way or the other) appropriate.
The elements of the predicate criminal offense frame our
probable cause analysis. Doe v. Gray,
75 F.4th 710, 719 (7th Cir.
2023). Wisconsin’s OWI statute states that “[n]o person may
drive or operate a motor vehicle while … [u]nder the influ-
ence of an intoxicant … [or] under the influence of any other
drug to a degree which renders him or her incapable of safely
driving.” WIS. STAT. § 346.63(1)(a).
Mr. Petersen does not dispute that he was intoxicated on
the night in question. Instead, his claim hinges on the conten-
tion that Deputy Pedersen did not have probable cause to be-
lieve that he had “drive[n] or operate[d]” his car that night.
He emphasizes that no one saw him operating the car and, on
that basis, argues there was no reason to believe he was the
person driving when it crashed into the yard.
Mr. Petersen’s argument misunderstands the probable
cause inquiry. The relevant question is not whether Deputy
Pedersen was certain that Mr. Petersen was driving while in-
toxicated. Rather, it is whether, under a totality of the circum-
stances, it was reasonable for Deputy Pedersen to arrest be-
cause there was a “sufficient probability, not certainty” that
No. 24-1206 9
Mr. Petersen violated the OWI statute. Hill v. California, 401
U.S. 797, 804 (1971). On the record before us, Deputy Pedersen
reasonably determined that there was a “substantial chance”
that Mr. Petersen crashed into the yard while driving intoxi-
cated, thus her arrest was supported by probable cause. Mu-
hammad v. Pearson,
900 F.3d 898, 908 (7th Cir. 2018) (quoting
District of Columbia v. Wesby,
583 U.S. 48, 57 (2018)).
The circumstantial evidence available contemporaneously
to Deputy Pedersen strongly supports this conclusion. When
she arrived at the scene, the details were clear: tire tracks ran
through the front yard, broken branches littered the ground,
and the tracks led to a driveway where Mr. Petersen was at-
tempting to change a tire on his car. Several bystanders re-
ported that he was the only person they saw near the vehicle
that evening. Deputy Pedersen attempted to question Mr. Pe-
tersen, but he responded belligerently and exhibited clear
signs of intoxication: he reeked of alcohol, his eyes were
bloodshot, his speech was slurred, and he was unsteady on
his feet. The timing of the arrest is also relevant; Deputy
Pedersen arrived roughly fifteen minutes after receiving the
dispatch call, making Mr. Petersen’s intoxicated presence next
to the car even more damning. Given the erratic tire tracks,
the state of the scene, and Mr. Petersen’s inebriation, the com-
mon-sense conclusion was that he had been driving the car in
the crash Deputy Pedersen was dispatched to investigate. See
United States v. Burnside, 588 F.3d 511, 518 (7th Cir. 2009) (“The
officers, employing even a modicum of common sense, had
probable cause to conclude that something illegal occurred.”).
On top of this, Deputy Pedersen also relied on her prior
knowledge and familiarity with Mr. Petersen. First, she knew
that Mr. Petersen and his daughter were estranged. This
10 No. 24-1206
allowed her to discredit his alibi that it was his daughter, not
him, who had crashed his car. Second, Deputy Pedersen knew
from her prior interactions with Mr. Petersen and from the
information she received from dispatch that he had several
prior OWIs, a BAC restriction on his license, and a suspended
driver’s license. Of course, standing alone, this evidence
could not establish probable cause for a drunk driving arrest
“on [this] particular occasion.” FED. R. EVID. 404(b)(1). But it
was appropriately considered by Deputy Pedersen—along
with the wealth of other information she had available—to es-
tablish probable cause under a totality of the circumstances
analysis. See Illinois v. Gates,
462 U.S. 213, 244–45 (1983).
The sum of the evidence therefore readily established
probable cause to arrest Mr. Petersen for drunk driving, and
for that reason, his false arrest claim against Deputy Pedersen
must fail. Mwangangi, 48 F.4th at 825.
This conclusion bleeds into our next, which is that, in any
event, Deputy Pedersen is undoubtedly shielded from liabil-
ity under qualified immunity. With respect to false arrest
claims, the central question for qualified immunity is whether
the officer had “arguable probable cause.” Id. “Arguable
probable cause exists when a reasonable officer in the same
circumstances and possessing the same knowledge as the of-
ficer in question could have reasonably believed that probable
cause existed in light of well-established law.” Huff v. Reichert,
744 F.3d 999, 1007 (7th Cir. 2014) (quoting Humphrey v.
Staszak,
148 F.3d 719, 725 (7th Cir. 1998)) (cleaned up). Because
Deputy Pedersen had actual probable cause to arrest Mr. Pe-
tersen, she necessarily acted with arguable probable cause.
Thus, she is entitled to qualified immunity even if the
No. 24-1206 11
existence of actual probable cause were less clean-cut than it
is here. Abbott,
705 F.3d at 718.
We end our discussion of Mr. Petersen’s false arrest claim
by briefly addressing a peculiar, albeit immaterial, aspect of
this case’s procedural history. Recall that the State dismissed
criminal charges against Mr. Petersen in Wisconsin state court
after the circuit court found that Deputy Pedersen lacked
probable cause to arrest him. For the first time, Mr. Petersen
argues on appeal that the state court’s probable cause ruling
should have preclusive effect in this case under the doctrine
of collateral estoppel.
This argument runs into issues right out the gate. First, Mr.
Petersen failed to raise this argument in the district court and
thus has forfeited it on appeal. Henry v. Hulett, 969 F.3d 769,
786 (7th Cir. 2020) (en banc). At any rate, even if we were to
assume that the state court’s probable cause ruling has pre-
clusive effect (though we are doubtful), it would be practi-
cally irrelevant here where Deputy Pedersen is shielded by
qualified immunity. 2 In other words, Deputy Pedersen would
still be entitled to summary judgment on the false arrest claim
2 Under Wisconsin’s collateral estoppel rules, which would apply
here, see Allen v. McCurry, 449 U.S. 90, 96 (1980), a party invoking preclu-
sion must prove that the issue “was actually litigated and determined in
the prior proceeding by a valid judgment[,]” and that “the application of
issue preclusion would be fundamentally fair.” Dostal v. Strand,
984
N.W.2d 382, 388 (Wis. 2023). The State voluntarily dismissed Mr. Pe-
tersen’s criminal case, so there was no “final judgment on the merits,” as
collateral estoppel requires. Teske v. Wilson Mut. Ins. Co.,
928 N.W.2d 555,
561 (Wis. 2019); see also Best v. City of Portland,
554 F.3d 698, 701 (7th Cir.
2009) (holding that Indiana state court’s suppression ruling did not have
preclusive effect in § 1983 action because the issue was not decided by a
“final judgment on the merits” due to government’s voluntary dismissal).
12 No. 24-1206
because she had arguable probable cause to arrest. See
Schimandle v. Dekalb Cnty. Sheriff’s Off.,
114 F.4th 648, 656 (7th
Cir. 2024) (“[A] determination of actual probable cause is sep-
arate and distinct from arguable probable cause.”). For these
reasons, Mr. Petersen’s last-minute invocation of collateral es-
toppel falls flat.
II. The Blood Draw
We turn now to Mr. Petersen’s claim that the unconsented
blood draw was an unreasonable search under the Fourth
Amendment. Police may not take a blood sample from a non-
consenting individual unless they obtain a warrant or the
search falls into one of the recognized exceptions to the war-
rant requirement. Missouri v. McNeely, 569 U.S. 141, 148
(2013). Here, Deputy Pedersen obtained a warrant. Neverthe-
less, Mr. Petersen contests the validity of the warrant by chal-
lenging the veracity of the sworn statements Deputy Pedersen
made to Judge Seifert during the telephonic warrant applica-
tion. He contends that Deputy Pedersen knowingly lied to
Judge Seifert by telling her that she witnessed him driving.
This claim is baseless.
“Searches undertaken pursuant to valid search warrants
are presumptively valid[.]” Archer v. Chisholm, 870 F.3d 603,
613 (7th Cir. 2017) (citing Franks v. Delaware,
438 U.S. 154, 171
(1978)). To be valid, the warrant must “(1) be issued by a neu-
tral and disinterested magistrate; (2) establish probable cause
that the evidence sought in the warrant will aid in obtaining
a conviction of a particular offense; and (3) describe with par-
ticularity the things to be seized and the place to be searched.”
Id. at 614. Challenging the veracity of an officer’s sworn tele-
phonic testimony supporting a warrant application is partic-
ularly “tough sledding” because such statements also carry
No. 24-1206 13
with them “a presumption of validity.” Suarez v. Town of Og-
den Dunes,
581 F.3d 591, 596 (7th Cir. 2009) (citing Franks,
438
U.S. at 165, 171).
Thus, to survive summary judgment Mr. Petersen had to
surface evidence that suggested Deputy Pedersen “know-
ingly or intentionally or with a reckless disregard for the truth
made false statements to the judicial officer,” and then show
that those false statements were “necessary to the judicial of-
ficer's determination that probable cause existed.” Id. (quot-
ing Molina v. Cooper,
325 F.3d 963, 968 (7th Cir. 2003)) (cleaned
up).
The record contains no evidence suggesting that Deputy
Pedersen made false statements to Judge Seifert. Deputy
Pedersen’s entire conversation with Judge Seifert was docu-
mented both through a circuit court transcript and her body-
worn camera footage. These sources confirm that Deputy
Pedersen did not claim anyone had seen Mr. Petersen driving
his car that night. As it turns out, they show that Judge Seifert
explicitly acknowledged the fact that no one had witnessed
him driving. R. 34-4 at 6 (“THE COURT: And did you—You
didn’t witness any driving? DEPUTY PEDERSEN: Correct.
THE COURT: [Did] the individuals that made the phone call?
DEPUTY PEDERSEN: They heard the crash and they were
coming outside. They said that they did not actually see it
happen.”). The transcript is clear. Mr. Petersen’s accusation
that Deputy Pedersen misled Judge Seifert is wrong.
Without any evidence that Deputy Pedersen misrepre-
sented facts, we easily find that the blood draw was executed
pursuant to a valid warrant. Mr. Petersen does not dispute
that Judge Seifert was neutral and disinterested, nor does he
contend that the warrant lacked particularity. Additionally,
14 No. 24-1206
we have already concluded that Deputy Pedersen had proba-
ble cause to believe Mr. Petersen was drunk driving, and no
new information available to her after the arrest disrupts this
conclusion. In fact, by the time she requested the warrant (af-
ter the arrest) she had an even stronger basis for probable
cause, having found car keys in his coat pocket and con-
firmed, through his mother, that he was estranged from his
daughter. Deputy Pedersen shared these additional facts with
Judge Seifert. Accordingly, Judge Seifert reasonably con-
cluded that the probable cause threshold was met, and that
there was reason to believe that a blood draw would provide
evidence of Mr. Petersen’s intoxication.
We therefore find that the blood draw was obtained pur-
suant to a valid warrant and was lawful. See Edwards v. Jolliff-
Blake, 907 F.3d 1052, 1057 (7th Cir. 2018). Having concluded
that Deputy Pedersen acted lawfully, we also agree with the
district court that she is entitled to qualified immunity. See
Archer,
870 F.3d at 614. (noting that an officer is “entitled to
qualified immunity if she is acting pursuant to a warrant that
was authorized by a judge, and her action is reasonable”).
CONCLUSION
Deputy Pedersen’s decisions to arrest Mr. Petersen for
drunk driving and to seek a BAC warrant were well sup-
ported by the information available to her and consistent with
our Fourth Amendment jurisprudence. Accordingly, we
AFFIRM the judgment of the district court.