21-year old Zachary Kranefield of Millville, N.J. is charged with possession of a prohibited device.
Police say they found a homemade smoke grenade inside the suspect's vehicle.
Kranefield works for the City of Ocean City Beach Patrol.
It was Tuesday evening when the report of a suspicious device prompted police to evacuate a stretch of Ocean City beachfront.
Action News was there as police cleared the sand around the lifeguard stand at 36th Street so they could detonate the device.
Whatever it was made a loud pop when the Atlantic City Bomb Squad blew it up.
It was a frighening scene for people in nearby homes.
"They moved everybody back, about two blocks further back. They told us we had to be inside, not on the porch. The bomb squad truck came in," said Bobby Spirk of Fountain Hill, Pa.
"And even at the beginning you could see people were evacuated immediately because there were beach chairs left behind, umbrellas. It was eerie. It was a ghost town on 36th Street," said Meredith Harrar of Abington, Pa.
Several people Action News talked to Tuesday night say they saw someone being taken into custody.
Ocean City Police said at the time there was no danger to the public.