It's illegal for the police to attach a GPS unit to your car without your permission, as the U.S. Supreme Court settled in 2012.But if the police are in hot pursuit of a bank robber or other escaping criminals that threaten public safety, a GPS tracker is acceptable. But exactly how can the police GPS track a car that is moving fast? The answer to that question comes from StarChase,a new police technology being used by a small but growing number of law enforcement agencies.It allows the police to fire 4.5-inch glue-covered GPS bullet-like projectiles from an air gun fixed in their police cars.If the GPS tracker makes contact with the escaping robber's car, it'll stick no matter how fast the vehicle is going.That way, the police will have a constant read on the car's location and heading.Aside from simply apprehending criminals,it's believed this new technology could help save lives.If the police successfully fire a GPS unit at a speeding criminal,they can pull back from a high-risk chase.Chases can be incredibly dangerous to all involved,including innocent bystanders and other drivers.Once the GPS bullet connects,there's no need for the chase any longer. Now,predictably,a GPS-loaded gun isn't cheap. Police departments need to pay about   $5.000 per vehicle for the technology,and individual GPS bullets cost as much as $250 each.That may sound expensive,but remember:The alternative is often thousands of dollars in property damage,and great human cost in injury and lost life.According to Star Chase,their GPS bullet system has an apprehension rate of 80%without any report of inury or property damage.If you'd like to learn more about the StarChase system,Popular Mechanics has just published a good article about it.There's also plenty more information available at the company's website. From the text we can learn that GPS bullets  _  .
are useful for the police are widely used in America can control the rising crime rate can replace the police in the future