By Mike Riggs, October 31, 2013

The Ford Bronco carrying O.J. Simpson (hidden in rear seat) is chased by dozens of police cars during an hour long pursuit through Los Angeles area freeways on June 17, 1994.
There's a lot of hype bubbling up over a new product aimed at helping police track fleeing suspects. The StarChase system being used by cops in Florida and Iowa
allows police officers to fire "a miniature GPS module encased in a
tracking projectile/tag" from a "launcher" mounted on a police cruiser's
grill. The GPS module then sticks to the rear of the fleeing car,
allowing dispatch to track the vehicle while the pursuing officer breaks
off.
Make no mistake: breaking off is most often a good thing. According to a 2010 FBI report on
pursuit policies, high-speed chases are often dangerous and
unnecessary. Breaking off the pursuit, meanwhile, has very few negative
consequences for crime-fighting. Various studies (all of them cited by
the FBI in the aforementioned report) have shown that once suspects
realize they're no longer being chased, they tend to slow down to normal
driving speeds. The FBI's report even rebuts the most frequently
excused argument for chasing suspects: "If the
police refrain from chasing all offenders or terminate their pursuits,
no significant increase in the number of suspects who flee would
occur."
So back to StarChase, this "revolutionary" GPS launching system: It has
some flaws. The cannon costs $5,000 and the non-reusable GPS "bullets"
cost $500 each. During a recent media demonstration,
four sticky bullets were fired at a car, but only one of them stayed
stuck. That failure rate could lead to some pretty ugly budget math,
though the cost of the system might still be cheaper than the cost of a
collision caused by a high-speed chase.
For instance, the police department in St. Petersburg, Florida, which
will now experiment with StarChase, initiated 26 high-speed chases last
year. Seventeen of those chases—65 percent—ended in collisions.
Twenty-six chases, with four $500 GPS trackers fired per chase, comes
out to $52,000 in ammo. That's surely less expensive than the damage
incurred through 17 collisions (especially last year's incident in
which a car thief, who had his two-year-old with him, drove into a city
bus; the two vehicles then veered off the road and into an apartment
building), but the cost of outfitting an entire fleet with $5,000
cannons would be a lot heftier. That's why departments are starting with
just a few. Troopers in Iowa have reportedly already used it to preclude a lengthy and likely dangerous chase.
But cost isn't the only concern. Last week the U.S. Court of Appeals for the 3rd Circuit ruled that police need a warrant to attach a GPS tracking device to a person's vehicle. U.S. v. Katzin concerned
federal agents who'd attached a GPS device to a suspected pharmacy
robber's car; the court ruled that by doing so, the Feds had created
"a police presence for the purpose of discovering evidence that may come
into existence and/or be placed within the vehicle at some point in the
future." That uninterrupted presence constitutes an unreasonable search
if there's not a warrant authorizing it. A year before the Katzin
ruling, the Supreme Court ruled in U.S. v. Jones that using GPS to track a car was indeed a search, but didn't say if a warrant was needed.
This is where StarChase may face an even bigger problem than the stickiness of its darts. The company's response to U.S. v. Jones explicitly
points to the absence of a warrant requirement as a reason why law
enforcement departments shouldn't fear legal challenges to their use of
the GPS dart. "By failing to state that a warrant is required," reads
StarChase's statement, "the Court left open the possibility that use of a
GPS tracking device on an automobile may still be a reasonable search
in some circumstances, such as immediately after the commission of a
crime, even absent a valid warrant."
There's also this: "The StarChase Pursuit Management System is
reasonable under the Fourth Amendment because the officers have probable
cause to believe the vehicle they are tracking is being used in the
commission or active escape from a crime." Basically, the company's
lawyers believe StarChase is legal one way or another.