L.A. Times 
Sunday, December 11, 2011
Reporting from Washington— Armed with a search warrant, Nelson County Sheriff Kelly Janke went looking for six missing cows on the Brossart family farm in the early evening of June 23. Three men brandishing rifles chased him off, he said.
Janke knew the gunmen could be anywhere on the 3,000-acre spread in eastern North Dakota. Fearful of an armed standoff, he called in reinforcements from the state Highway Patrol, a regional SWAT team, a bomb squad, ambulances and deputy sheriffs from three other counties.
He also called in a Predator B drone.
As the unmanned aircraft circled 2 miles overhead the next morning, sophisticated sensors under the nose helped pinpoint the three suspects and showed they were unarmed. Police rushed in and made the first known arrests of U.S. citizens with help from a Predator, the spy drone that has helped revolutionize modern warfare.
But that was just the start. Local police say they have used two unarmed Predators based at Grand Forks Air Force Base to fly at least two dozen surveillance flights since June. The FBI and Drug Enforcement Administration have used Predators for other domestic investigations, officials said.
Full story here.