The man who allegedly shot a veteran Long Island police officer showed no remorse Thursday morning as he pleaded not guilty to charges that could put him behind bars for life.

Wearing a white jumpsuit and debuting a fresh black eye, 22-year-old Sheldon Leftenant was held without bail on charges of attempted aggravated murder and resisting arrest for allegedly opening fire on an on-duty, plainclothes police officer Wednesday night.

Leftenant allegedly shot Officer Mark Collins twice in the neck and hip during a traffic stop just before midnight. He was found just blocks from the scene following a manhunt throughout Huntington Station.

Collins, a 12-year veteran of the Suffolk County Police Department, was being treated at Stony Brook University Hospital with non-life-threatening injuries, sources said.

The 35-year-old decorated cop works in the gang unit.

He was named cop of the year in 2008 for a harrowing incident involving a high-speed chase of a gunman.

He’s also received a Bravery Gold Medal for saving an elderly handicapped man from a house fire that left Collins with a burned face and lacerations.