terms of the settlement are confidential., page-5

using compressed air..

http://www.starchase.org/uploads/sc_brochure.pdf

The StarChase System Is Simple to Operate

1.A compressed-air launcher, mounted behind the grille of a police cruiser, uses a laser to target the fleeing vehicle. It discharges a projectile/tag containing the GPS module.
2.The projectile adheres to the suspect vehicle and transmits coordinates back to dispatch.
3.The dispatcher then views the location and movements of the tagged vehicle in near real-time on a digital roadmap via a secure Internet connection