Adelphi, Md. ? A man who police say killed two deputies as they tried to take him away for emergency psychiatric care remained at large Friday and was believed to be armed.

James Logan, 23, hid in a bedroom of his parents’ house Thursday, then shot the sheriff’s deputies with a handgun when they confronted him, said Capt. Andrew Ellis, a spokesman for the Prince George’s County Police Department.

“They were caught completely by surprise. It appears it was a very quick and violent event,” Ellis said.

Police found what they said was Logan’s getaway vehicle in a nearby neighborhood, and officers there handed out fliers with his picture. Search dogs also were being used.

County police Chief Gerald M. Wilson said Logan was believed to have the handgun used to kill Cpl. James V. Arnaud, 53, and Deputy Sheriff Elizabeth Licera Magruder, 30. Arnaud died at the scene and Magruder died a short time later at Prince George’s Hospital Center.

The deputies were serving a mental health warrant that Logan’s wife had sought because he was behaving erratically, two police sources familiar with the investigation said. Logan has a history of mental and emotional problems and violent behavior, said the sources, who spoke on condition of anonymity.

Investigators on Friday questioned a man they said was at the home when the shootings occurred and left with Logan. Police said the man, whom they did not identify, wasn’t believed to be involved in the shootings.

As word of the deaths spread, more than a hundred law enforcement officers gathered at the hospital, some crying or hugging outside the emergency room.

Sheriff Alonzo Black called the killings “the most serious tragedy that has ever occurred to the office of sheriff.”