To end high-speed chases without resorting to gunfire, cops lay strips of tire-shredding spikes in a fleeing vehicle's path. But placing them on the road can be hazardous work: Officers are often struck by swerving cars and flying debris after setting up the spikes, which must be deployed right as the fugitive approaches. Eric Spencer was stunned when his brother, a longtime police sergeant, explained the perils at a family dinner. “Doing it all by hand seemed like the dumbest thing ever,” recalls Spencer, a patent attorney in Finksburg, Maryland. His preteen son suggested deploying them from afar—an idea that struck Spencer as ingenious.

Behold DynaSpike, a tire-puncturing system operated by remote control. By pressing a button from a safe distance, a cop can make the gadget's spikes spread across a lane and a half of traffic in 1.5 seconds. The power source is a canister of compressed air that can be recharged by a car's cigarette lighter in a few minutes. Though the $1,700 DynaSpike is about three times more expensive than manually deployed spikes, a dozen police departments from New Mexico to Pennsylvania have purchased it. Spencer doesn't have stats on how often the DynaSpike has helped nab fugitives, but he's certain that no cops have been harmed while pressing the button.