Three suspects have been charged with first-degree murder in the slaying of Antonio M. Kelsey, an off-duty Prince George's County police officer who was shot Saturday outside a Landover liquor store where he worked as a part-time security guard.

Steven Baines, 27, of 2663 Bowen Rd. SE, went to the 1st District police headquarters Sunday night and was held as a fugitive from Prince George's where he is charged with murder, police said.

Two other suspects, Charles L. Mayhew, 28, of 1179 Marcy Ave., Oxon Hill, and Cheryl Lynn Talbert, 24, 1121 Dunbar Oaks Dr., Seat Pleasant, were arrested and held without bond by Prince George's police.

Kelsey, 22, who had served on the county police force for 13 months, died after being shot in the head with his own gun, according to police accounts.

Kelsey worked at Cox's Liquors in Landover as a part-time security guard, in uniform, which he was permitted to do under police regulations. Shortly before 9 p.m., according to police, two persons entered the store and one displayed what appeared to be a bag of marijuana. He held the bag of marijuana up, according to the store cashier, and taunted Kelsey.

The man's female companion began shoving him out the door, according to police and Kelsey radioed Seat Pleasant police headquarters and said he was pursuing a man on foot. Those were Kelsey's last known words, according to a police spokesman.

Police who responded to Kelsey's call a short while later found him sprawled on a patch of grass near the store, shot in the head.