LOWELL, Mass. (AP) _ A murder suspect shot himself before his arrest but his wounds went undetected for a day until he complained of headaches, and a brain scan revealed bullet fragments in his ear, a prosecutor said today.

Vuthy Seng, 34, was being held without bail after pleading innocent Monday to charges of armed assault with intent to commit murder. He was accused of shooting his live-in girlfriend's four children with a .22-caliber gun after she asked him to move out.

Prosecutors expected to charge him with murder today. One of the children, Virak Men, 12, died at a hospital Monday.

``After the incident, after the children were shot, he tried to shoot himself,'' District Attorney Thomas Reilly said. ``It wasn't readily apparent and he didn't complain. He complained of headaches.''

Hospital officials confirmed Seng had been admitted but would not comment further.

Two boys, 15-year-old Visal, who had also been hacked with a machete, and 9-year-old Sovanna, were in critical condition. Their sister, 14-year-old Sathy, was in fair condition, hospital officials said.

``She tried to tell him to get out of the apartment because the kids didn't like him and she doesn't like him,'' said Chuop Ream, the children's aunt. She said Seng and the children's mother, Chong Yim, had been living together for about two months.