
Vol. 78, No. 6, June 
2005
Cell phone tips of crime and 'reasonable suspicion'
With the proliferation of cell phone use comes an increase in the 
number of criminal investigations arising from cell phone reports of 
ongoing or just completed criminal activity. Read how traditional 
"reasonable suspicion" analysis has evolved in response to the use of 
this new technology.
 
Sidebars:
by Rex R. Anderegg

 ew technological innovations have had greater 
impact on the reporting of crime than the cell phone. According to the 
Cellular Telephone Industry Association, there are currently more than 
175 million cell phone subscribers in the United States, and a recent 
study revealed more than 54 percent of drivers carry wireless phones in 
their vehicles.1 This article examines how 
traditional "reasonable suspicion" analysis has evolved to respond to 
the use of this new technology in reporting crimes.
ew technological innovations have had greater 
impact on the reporting of crime than the cell phone. According to the 
Cellular Telephone Industry Association, there are currently more than 
175 million cell phone subscribers in the United States, and a recent 
study revealed more than 54 percent of drivers carry wireless phones in 
their vehicles.1 This article examines how 
traditional "reasonable suspicion" analysis has evolved to respond to 
the use of this new technology in reporting crimes.
A strong correlation exists between the great proliferation of 
wireless technology and the frequency with which police investigations 
now begin with a cell phone call from the scene of a crime. Every year 
more than 73 million calls are placed to 9-1-1 hotlines from cell 
phones.2 While many of these calls are 
placed for emergency medical assistance, an increasing percentage of 
such calls are to report crime. The primary significance of this 
development to the criminal justice system is that crimes, particularly 
driving offenses, are now routinely reported while still in progress, 
thereby giving rise to an urgent desire by law enforcement to act 
quickly. Acting quickly, however, oftentimes means acting with limited 
information. Investigative detentions based on limited information, in 
turn, frequently beget suppression motions challenging whether there was 
reasonable suspicion to stop the defendant.
 Rex R. Anderegg, U.W. 1989, is a 
partner in Anderegg & Mutschler LLP and manages the firm's 
Milwaukee office. The firm's emphasis is in criminal and traffic 
defense, as well as appellate practice and procedure. He was appellate 
counsel on the Larson case.
Rex R. Anderegg, U.W. 1989, is a 
partner in Anderegg & Mutschler LLP and manages the firm's 
Milwaukee office. The firm's emphasis is in criminal and traffic 
defense, as well as appellate practice and procedure. He was appellate 
counsel on the Larson case.
The author thanks legal assistant Julie Guvernator, whose significant 
contributions to this article made its publication possible.
 
The courts have responded to such reasonable suspicion challenges by 
posing, evaluating, and answering several questions. Is the tipster 
truly anonymous or does she identify herself? Is it possible to trace 
the call back and identify the caller if the tip is fabricated? What is 
the basis of the caller's knowledge about the alleged criminal behavior? 
How serious is the alleged crime? How immediate of a threat does the 
alleged criminal behavior pose to the public? Is the caller reporting a 
crime in progress or a crime that has already occurred? Many of these 
inquiries have historically been important to courts when examining the 
question of reasonable suspicion. However, as explained in this article, 
what is of particular significance to reasonable suspicion analysis is 
the elevated status, within the reasonable suspicion paradigm, being 
granted to those specific inquiries that focus on exigency.
The U.S. Supreme Court on Anonymous Tips
At the turn of the millennium, the U.S. Supreme Court took a fresh 
look at the implications of cell phone tips on the Fourth Amendment. The 
backdrop presented in Florida v. J.L.3 was a report from an anonymous tipster that a 
young African-American male at a bus stop was carrying a gun. Applying 
its rulings in Adams v. Williams4 
and Alabama v. White5 regarding 
informants' tips to its reasonable suspicion analysis from Terry v. 
Ohio,6 the Supreme Court held that an 
anonymous tip that a readily identifiable teenager at a particular bus 
stop possessed a gun was not, without more, sufficient to justify a 
Terry stop of the youth.7 The 
decision hinged largely on the fact that the Supreme Court did not view 
the tip as particularly reliable in its assertion that illegal behavior 
had occurred. The J.L. court noted that a tip's reliability is 
a function of the informant's credibility and the basis of his or her 
knowledge. The Supreme Court reasoned that it is not enough that an 
informant provides readily observable details about a suspect if the 
informant cannot also demonstrate "inside knowledge" about the suspect's 
criminal behavior. Because the bus stop tip came from an anonymous 
caller and lacked any predictive information other than the subject's 
easily observable location and description, police were left with no 
means to test the informant's credibility or basis of knowledge.8
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Florida, however, citing the danger posed by firearms, urged the 
Supreme Court to modify its standard Terry analysis to allow 
for a "firearm exception" to the reasonable suspicion requirement. The 
Supreme Court flatly rejected the request on the ground that creating 
such an exception would lead to a slippery slope of additional 
exceptions, "thus allowing the exception[s] to swallow the rule."9 Although possession of a weapon by anyone under 
age 21 was illegal in Florida, and notwithstanding the obvious danger 
posed by a youngster allegedly packing heat in public, the Supreme Court 
did not consider the danger to be so imminent as to support a stop and 
frisk. The pre-9/11 Supreme Court refused to speculate about the 
circumstances under which the danger alleged in an anonymous tip might 
be so great (for example, a report of a person carrying a bomb) 
as to justify a stop and search even absent any showing of 
reliability.10 Nevertheless, the Supreme 
Court did observe that "extraordinary dangers sometimes justify unusual 
precautions," and thus the seeds of an exigency analysis - seeds that 
would later bear fruit in Wisconsin - were sown.
Of particular interest was a concurring opinion by Justice Kennedy, 
who observed that to the extent an informant remains completely 
anonymous and does not place her identity at risk, such an informant is 
free to lie with impunity. Since a court would be powerless to judge the 
credibility of such an individual, the risk of fabrication, in Justice 
Kennedy's view, would be unacceptable.11 
Justice Kennedy went on to suggest, however, that if an informant were 
to reveal her identity and thereby expose herself to criminal penalties 
for making a false report, such a factor would be fair game for a 
judicial assessment of the tip's reliability. Those facts were not 
before the J.L. court, however, and a discussion of such a 
scenario was therefore left for another day. In Wisconsin, that day 
dawned roughly one year later.
The Importance of Identifying the Tipster
In July 2001, the Wisconsin Court of Appeals was presented with 
circumstances similar to those in J.L. The Wisconsin court, 
however, reached a different conclusion solely because the 9-1-1 caller 
provided the name "Sedrick Forbes" to the dispatcher, who identified the 
call as coming from a payphone.12 Like the 
tipster in J.L., Forbes reported seeing two men with guns 
entering a building and described their race and clothing. On the basis 
of the tip, police located two men matching the suspects' descriptions 
sitting in a car a half-block from the building in question. After 
briefly questioning the suspects, the police asked one of them, Sisk, to 
exit the vehicle and then frisked him and found a gun in his pants 
pocket. Sisk was charged with being a felon in possession of a 
firearm.
Relying on J.L., the trial court reasoned that a 9-1-1 call 
from a payphone, even with the caller's name, imbued the tip with no 
greater reliability than would an anonymous report, because there was 
nothing to link the call back to the caller if the report was false. The 
trial court further observed that the tip gave no predictive information 
about the alleged criminal activity and provided only a readily 
observable description of the alleged gun-toters. Although the trial 
court's rationale seemed faithful to J.L., the appellate court 
viewed the matter differently and reversed the order that had suppressed 
evidence of the firearm. The appellate court reasoned that it was error 
to characterize the tip as anonymous since the 9-1-1 caller had put his 
identity at risk by providing "what he said was his name."13 Sisk therefore breathed life into 
Justice Kennedy's concurrence, albeit on facts less compelling than 
Justice Kennedy might have contemplated. In so doing, Sisk 
observed it would be dangerous to require police to take time to verify 
the caller's identification rather than respond to a crime in 
progress.14
The Immediate Public Danger Suggested by the Tip
The same year Sisk was published, the Wisconsin Supreme 
Court addressed whether a cell phone caller's anonymous tip about the 
driving of a vehicle the caller was following was ipso facto sufficient 
to warrant a traffic stop. The tipster reported that the vehicle was 
tailgating, weaving within its lane, and varying in speed from too fast 
to too slow. In State v. Rutzinski,15 the Wisconsin Supreme Court, drawing on factual 
distinctions alluded to by J.L., observed that although the 
cell phone caller did not provide his name, he did tell the responding 
officer (via dispatch) the location of his car vis-a-vis the suspect's 
car. The court reasoned that by doing so, he exposed himself to 
identification (through the tracing of his license plates) if he was 
fabricating the tip. In addition, he had provided to the dispatcher 
contemporaneous information about Rutzinski's driving as he was 
following the vehicle.16
The Wisconsin Supreme Court began its analysis by acknowledging that 
before an officer may detain an individual solely on an informant's tip, 
the officer must first consider both the veracity of the informant and 
the content of the tip as it relates to the informant's basis of 
knowledge of the alleged illegal activity.17 If the tipster's credibility and basis of 
knowledge are weak, additional investigation is needed before reasonable 
suspicion will support a Terry stop. Because the test, however, 
requires consideration of the totality of the circumstances, the court 
noted that a deficiency in one consideration may be compensated by a 
strong showing as to the other.18
The most interesting aspect of the Rutzinski decision, 
however, was its introduction of exigency into the analysis. Recalling 
J.L.'s admonition that "extraordinary dangers sometimes justify 
unusual precautions," the Wisconsin Supreme Court ruled that in some 
circumstances, an exigency can supplement the reliability of an 
informant's tip and justify what would otherwise be an improper 
investigative stop.19 Cognizant that its 
decision would be subject to scrutiny under the holding in 
J.L., the Rutzinski court identified three factors 
that distinguished the facts before it from the anonymous report about 
an armed youth at a bus stop: 1) by giving the location of his vehicle, 
the informant exposed himself to identification by police; 2) the 
informant provided police with verifiable information indicating his 
basis of knowledge; and 3) the tip suggested Rutzinski posed an imminent 
threat to public safety.20 The court 
believed the first two of these factors increased the reliability of the 
tip while the third factor tipped the scales in favor of an immediate 
stop. Thus, leaning heavily on the danger posed by potential drunk 
drivers, Rutzinski held that the immediate threat posed by the 
reported erratic driving overcame any lack of reliability demonstrated 
by the anonymous tip and, therefore, that the traffic stop was 
reasonable.21
A Blanket Rule for OWI Cases?
While Rutzinksi explicitly stopped short of creating a 
blanket rule to except tips alleging drunk driving from a reliability 
requirement, that nevertheless may be the practical import of the 
decision. As Justice Kennedy suggested, there may be cases in which 
identification of the tipster and exposure to penalties for submitting a 
false police report would enhance the reliability of an otherwise 
"anonymous" tip. While this premise rings true when a tipster alleges 
that the subject, for example, is carrying a concealed weapon or 
possesses illegal drugs, either of which can be "immediately verified at 
the scene," the underlying logic is less compelling when the tipster 
alleges bad driving.
When an officer relies on such an allegation to stop a vehicle 
without independently observing any bad driving - an act largely 
sanctioned by Rutzinski - it is difficult to discredit the 
allegation that prompted the stop. In such a scenario, the putative 
exposure to criminal penalties for making a false report appears to be 
largely a fiction. Indeed, it does not even appear necessary for a 
tipster to specifically allege "drunk" driving (which arguably could be 
verified at the scene of a stop) to create an imminent threat to public 
safety. A report of any bad driving, in turn characterized by a 
dispatcher as "erratic" driving, has been interpreted by courts as 
indicative of "drunk" driving and grounds for an immediate investigation 
of the driver.22 Consequently, 
notwithstanding the Rutzinski court's pledge, there does appear 
to be something of a blanket rule allowing immediate detentions of 
drivers reported to be driving erratically, at least when the informant 
provides - ala Sisk - a name. This may be due, in part, to the 
fact that the presumption of unreasonableness that attends a warrantless 
seizure in a home is not present during traffic stops.23
When Does an Exigency Dissipate?
One question the Wisconsin Supreme Court has not addressed is when 
the exigency posed by erratic driving dissipates such that an 
uncorroborated stop or detention of a driver is no longer lawful. By 
examining both published and unpublished opinions of the court of 
appeals, however, one can piece together a rough answer to this 
question. In an unpublished opinion, the court of appeals was not 
persuaded that the urgency of a public threat evaporated simply because 
the driver was within a block of his home.24 Nor was the appellate court, in another 
unpublished opinion, convinced the threat had sufficiently passed even 
though the driver had just pulled into her driveway.25 The latter unpublished decision held that 
although the suspected drunk driver had reached what the officer knew to 
be her driveway, and had exited her car before the officer was able to 
reach her, a tip suggesting that she had been driving while intoxicated 
with two minor children in her vehicle strongly weighed in favor of 
immediate police investigation.26
State v. Larson, a published opinion, however, strongly 
suggests the exigency may evaporate once the suspect crosses his or her 
doorstep.27 In Larson the court of 
appeals addressed whether a warrantless entry into a suspected drunk 
driver's home, based on two tips, one from a gas station clerk and both 
from individuals who identified themselves, was reasonable under the 
Fourth Amendment.28 On the basis of the 
tips, the dispatcher provided a patrol deputy with the vehicle's license 
plate and the registered owner's address. The deputy drove to that 
address, observed the vehicle in an apartment complex parking lot, and 
knocked on the registered owner's door. When the defendant opened the 
door, the deputy immediately stepped across the threshold to prevent the 
defendant from closing the door. During a short conversation in which 
the defendant admitted drinking and stated he was going to bed, the 
deputy detected an odor of intoxicants and slurred speech and therefore 
moved further into the apartment to arrest the defendant for operating 
while intoxicated.
The defendant argued that the deputy lacked probable cause and 
exigent circumstances to overcome the presumption that the warrantless 
home entry was unreasonable. The court of appeals agreed. The court 
first confirmed that the step across the threshold was an entry under 
the Fourth Amendment.29 It then observed 
that the deputy lacked probable cause because at that time, he knew only 
that two tipsters had alleged the driver of the truck found parked 
outside the apartment was driving while intoxicated. At that precise 
moment, the deputy could neither have detected the odor of intoxicants 
on Larson's breath or his slurred speech nor known whether Larson was 
the driver of the truck. Most interesting to the question of exigency, 
however, was the appellate court's remark that even if the deputy could 
have established probable cause to enter Larson's home, no exigent 
circumstances justified the entry.30 
Indeed, any court contemplating an extension of the concept of exigency 
to include a driver who is safely at home will have to contend with 
Welsh v. Wisconsin,31 in which the 
court long ago held that in cases involving minor traffic offenses, a 
warrantless home arrest cannot be upheld simply because blood alcohol 
will dissipate while police obtain a warrant.32 Moreover, while the prosecution attempted to 
characterize the deputy's investigation as a "hot pursuit" of Larson, 
the appellate court dismissed that argument because there was no 
immediate or continuous pursuit of the defendant.
Establishing What Information was Known to the Investigating 
Officer
As noted at the outset of this article, cell phone reports prompt 
police to act with limited information. Defense attorneys should be 
aware that the amount of information available at the time of a 
suppression hearing, however, is oftentimes more plentiful than when the 
police first acted. Police reports, dispatch audiotapes, and written 
statements from the informant will materialize to put meat on the bare 
bones information the officer on the street originally possessed. 
Prosecutors will capitalize on this development by arguing that an 
officer's belief may be partially predicated on hearsay information and 
that the officer may rely on the collective knowledge of the officer's 
entire department.33 On the surface, the 
point is well taken.
A more profound examination of the applicable case law, however, 
suggests that defense attorneys should not let this position go 
unchallenged. While information generally in the possession of a law 
enforcement agency may be imputed to a particular officer, the 
proposition holds true only if the officer, when he or she acts, 
actually has the benefit of that information via communication with 
others in the agency.34 Thus, to the extent 
prosecutors wish to rely on information possessed by an investigating 
officer's colleagues, prosecutors should be prepared to demonstrate 
timely communication of the information to the officer. Conversely, 
defense attorneys should endeavor to establish what information actually 
was conveyed to the investigating officer and limit the court's analysis 
accordingly.
Conclusion
As wireless technology continues to improve and proliferate, so too 
will the number of criminal investigations hastily commenced by reports 
of ongoing or just completed criminal activity. Prosecutors and defense 
attorneys alike should be prepared to analyze the lawfulness of the 
Terry stops that will flow from such investigations. The 
analysis must center on what information is available to the officer who 
makes the stop. In particular, both sides should focus on whether the 
tipster identifies herself and what basis she has to make the particular 
allegations.
In light of Rutzinski, counsel also should examine the tip 
in terms of what immediate danger it suggests is facing the public at 
large, keeping in mind the trend toward viewing exigency as the 
touchstone of reasonable suspicion analysis. The societal benefits of 
wireless technology in terms of public safety and crime-solving have 
been immense. As is so often the case with technological advances, 
however, there is a corresponding threat to the individual's interest in 
freedom from unreasonable police detention. In the case of cell phones, 
the danger stems from the ease with which a police investigation can be 
set in motion based on what appears to be suspicious, but may ultimately 
turn out to be innocuous, activity. Attorneys must be prepared to assist 
the courts in striking a reasonable balance between these competing 
interests.
Endnotes
1National Highway 
Transportation Safety Administration.
2AAA Newsroom, Help with Auto 
Repairs is as Convenient as your Cellular Phone, Oct. 28, 2004.
3Florida v. J.L., 529 U.S. 
266 (2000).
4Adams v. Williams, 407 
U.S. 143 (1972).
5Alabama v. White, 496 
U.S. 325 (1990).
6Terry v. Ohio, 392 U.S. 1 
(1968).
7J.L., 529 U.S. at 
269-74.
8Id. at 271.
9Id. at 273.
10Id. at 273-74.
11Id. at 274-75.
12State v. Sisk, 2001 WI 
App 182, 247 Wis. 2d 443, 634 N.W.2d 877.
13Id. ¶ 8.
14Id. ¶ 9.
15State v. Rutzinski, 
2001 WI 22, 241 Wis. 2d 729, 623 N.W.2d 516.
16Id. ¶¶ 
31-37.
17Id. ¶ 18.
18Id. (citing 
Illinois v. Gates, 426 U.S. 213, 233 (1983)).
19Id. ¶ 26.
20Id. ¶¶ 
32-36.
21Id. ¶¶ 
34-35.
22See id. ¶ 34 
(citing State v. Swanson, 164 Wis. 2d 437, 453 n.6, 475 N.W.2d 
148 (1991)).
23State v. Pallone, 236 
Wis. 2d 162, 190, 613 N.W.2d 568 (2000).
24State v. Christopher, 
No. 01-2524-CR, 2002 WL 31074663 (Wis. Ct. App. Sept. 18, 2002) 
(unpublished).
25State v. Baer, No. 
01-0423-CR, 2001 WL 864284 (Wis. Ct. App. Aug. 1, 2001) 
(unpublished).
26Id. ¶ 11.
27State v. Larson, 2003 
WI App 150, ¶ 9, 266 Wis. 2d 236, 668 N.W.2d 338.
28Id. ¶ 9.
29Id. ¶ 11.
30Id. ¶ 17.
31Welsh v. Wisconsin, 
466 U.S. 740 (1984).
32Id. at 754.
33State v. Cheers, 102 
Wis. 2d 367, 386, 38889, 306 N.W.2d 676 (1981).
34See State v. 
Orta, 2000 WI 4, ¶ 23, 231 Wis. 2d 782, 604 N.W.2d 543 (citing 
State v. Friday, 147 Wis. 2d 359, 434 N.W.2d 8 (overruled on 
other grounds)).
Wisconsin 
Lawyer