A 25-year-old Lorton Reformatory inmate was stabbed to death early yesterday as he walked from his cell block to breakfast in the maximum security section of the prison, D.C. Department of Corrections officials reported.

Otis Peterson, who was serving a sentence of 25 years-to-life for murder, armed robbery and other convictions, was attacked at about 5:45 a.m. by one or more assailants, according to corrections spokesman James Freeman. Peterson was pronounced dead on arrival about an hour later at DeWitt Army Hospital at Fort Belvoir from multiple stab wounds to the head, neck and back.

Freeman said two weapons and some bloody clothing were found concealed near the spot where the stabbing occurred. The homemade sword-like "shanks," each 18 inches or longer and fashioned from steel rods, were found in a trash can and in a drain pipe. One of them bore fresh blood stains.

The weapons were turned over to the FBI to determine whether they had been used in the stabbing, and whether they could lead to the assailant or assailants. The bureau is investigating the slaying because Lorton, a District prison, stands on federal land.

Peterson, a D.C. resident, was the second inmate stabbed to death in the maximum security unit in two months. James Bryant died in a similar manner on Christmas Eve.