A Prince George's County police officer who was moonlighting as a security guard at a party last weekend was suspended after he allegedly hit an unarmed college student in the mouth, then briefly placed the young man in a chokehold, officials said.

The officer, Dominique Richardson, was suspended Tuesday night, police officials said. Police have launched an internal investigation, said Maj. Andrew Ellis, a police spokesman.

Richardson, who is assigned to District I in Hyattsville, did not respond to a phone message left at his police station Tuesday.

Half of a front tooth was almost knocked out in Steven Morales, 20, of Waldorf, a student at the College of Southern Maryland, Morales and his attorney, Terrell N. Roberts III, said. A dentist has said Morales will eventually lose the tooth, Roberts said.

Morales said he was near the door of a warehouse on Somerset Avenue in Beltsville, where the party took place, about 1 a.m. Saturday. Morales said he had a ticket for the event. A man wearing a Prince George's police badge around his neck - Richardson, according to county police - was acting as a security officer, guarding the entrance.

Morales said there was not a single-file line, and he was surrounded from behind and from both sides by people trying to get into the warehouse.

Morales said he asked the officer, politely, "Can you help me?" The officer told Morales to get in line, Morales said.

Morales said he responded that he couldn't because he was hemmed in.

The crowd kept pushing forward, Morales said. Morales said he may have been pushed into the officer. If he did make contact, "it wasn't that hard of a push," Morales said. About the same time, he said, he asked the officer for help.

The officer grabbed him with one hand, reared back with his free arm and slugged him in the mouth, Morales said. Morales said he fell backward as other partygoers scattered. The back of his head bounced off the concrete, Morales said. The officer briefly put him in a chokehold, Morales said.

Another officer picked him up and put him against the hood of a police car, Morales said.

Morales said he turned around, and Richardson said, "Get the [expletive] out of here."

Neither officer accused him of a crime or asked whether he needed medical attention, Morales said.

Morales drove home and told his father, Luciano Morales, a 22-year veteran of the D.C. police, what had happened. The older Morales, who was dressed in his uniform, preparing for his work shift, drove his son back to the warehouse.

Luciano Morales said he and Steven met with Richardson. Richardson acknowledged that he hit Steven and accused Steven of assaulting him, Luciano Morales said. Richardson did not explain why he did not arrest someone who assaulted him, Luciano Morales said.

Luciano said his son was so bloodied that he initially thought he had been stabbed. "I know there are bad officers everywhere, but this touched home," Luciano Morales said.