Commercial drones are typically used to capture aerial footage, but some inventive criminals are using the unmanned craft to drop contraband into prison yards.
Authorities have documented multiple incidents where drones carrying contraband ranging from cellphones to methamphetamine and hacksaw blades have flown inside the perimeter of Delano's Kern Valley State Prison, according to court documents.
Prison staff found a crashed drone in September next to a medical trailer by Receiving and Releasing, California Department of Corrections and Rehabilitation investigator Jelani Hunter wrote in a search warrant.
The Phantom 3 Standard Drone was equipped with a modified release mechanism and its lights were covered with black electrical tape in an apparent attempt to keep it from being seen at night, Hunter wrote.
In a black cloth bag attached to the release mechanism investigators found an LG cellphone, two Samsung 4G cellphones, chargers and SIM cards.
"Inmates have figured out ingenious ways to introduce contraband into Kern Valley State Prison," Hunter wrote in the warrant. "In this matter, a quadcopter was flown over KVSP with the attempt to smuggle contraband into the institution perimeter."
Through the search warrant, investigators retrieved flight log data for the drone and its IP address. Investigators, however, were unable to make an arrest as multiple phone numbers were linked to the IP address.
The investigation is ongoing.
In another incident, on Feb. 1, a sergeant at KVSP heard a noise described as sounding like a drone flying over one of the prison yards, according to a search warrant. The sound of something hitting dirt was heard a short time later.
Prison staff located a black nylon drawstring bag in front of one of prison buildings. Inside were cellphones, chargers, SIM cards, headphones, tweezers, hacksaw blades, 180 grams of suspected heroin and 69 grams of suspected meth.
The following day, staff found three more bags containing drugs, lighters and rolling papers, among other items, the warrant said.
As with the earlier case, the investigation is ongoing.
Other counties have experienced similar problems.
In October, a drone crashed inside the perimeter of Elmwood Correctional Facility in Santa Clara County, according to KPIX 5. Investigators found a package of meth on board.
The Federal Aviation Administration requires drone users to register their aircraft. Operating rules include keeping the aircraft within visual line-of-sight, flying at or below 400 feet and the aircraft must weigh less than 55 pounds.