An off-duty police officer investigating the sound of gunfire last night found a wounded man outside an apartment complex in Hyattsville, and then shot and wounded another man who turned toward him with a handgun, police reported.

The man wounded before the officer arrived and the man shot by the officer were reported in serious but stable condition at area hospitals. The man whom the officer wounded and two others were arrested and charged with assault with intent to murder, police said.

Hyattsville Police Lt. Wayne McCully said the incident occurred about 10 p.m. when city police Cpl. Jerome Hampton, 28, who was wearing civilian clothes, heard gunfire. When Hampton, who lives in the neighborhood, went to investigate, he found the wounded man outside an apartment complex at 2705 Nicholson St., McCully said.

Hampton identified himself as a police officer and ordered one of three men at the scene to drop a gun he was holding, McCully said. When the man turned toward Hampton with the gun, the officer fired, striking the man in the stomach, according to McCully.

Other officers then arrived, McCully said, and helped Hampton arrest the three men.

The man who was initially wounded was taken to Prince George's Hospital Center, and the man shot by Hampton was taken to Washington Hospital Center, McCully said. The identities of the wounded and those arrested were withheld pending further investigation.