A transit security officer was killed in what appeared to be a violent robbery in the Flatlands section of Brooklyn early yesterday, police officials said.

James Plocica, a New York City transit security guard, finished his eight-hour shift at the Linden Subway Yard in Brooklyn at about midnight. He was waiting at a bus stop an hour later when an assailant or assailants shot him in the chest before running off with his backpack.

The bag, which contained a thermos and a brown bag of food, was found more than a block away along with a credit card with Plocica’s name on it.

A neighbor, Mary Campbell, said Plocica’s mother said his iPod might have been taken. Police said they have no description of the perpetrator or perpetrators of the attack.

A woman shopping with her children near the site of the killing, Kimyl Bacchus, said she would be more careful after the seemingly random attack.

“It’s not the kind of thing that happens around here,” she said.