At least 3 dead after 3-day standoff in Trenton, N.J.

Updated 11:32 a.m. ET

TRENTON, N.J. The bodies of a woman and her 13-year-old son were found after a dayslong standoff, and her boyfriend was killed as officers stormed the home to rescue three other children he had been holding captive, authorities said Sunday.

Police officers went to the South Trenton home Friday afternoon after reports that some of the children hadn't been to school in 12 days, authorities said at a Sunday news conference. Officers entered the home through a rear door and smelled an odor consistent with that of a decomposing body, Trenton Police Director Ralph Rivera Jr. said.

They found 38-year-old Gerald Tyrone Murphy in an upstairs bedroom, and he told them he was armed with a gun and explosives and had three children with him, Mercer County Prosecutor Joseph L. Bocchini Jr. said. Officers retreated from the second floor and rescued a 19-year-old man from the basement, who said he hadn't seen his mother or siblings since about April 24.

Homes on the surrounding block were evacuated as a precaution, and police tape cordoned off the street in front of the house. A SWAT team was called, and an arson bomb unit was also on the scene. Police said Murphy could be seen from a window holding a black handgun.

Police remained in contact with Murphy throughout the 37-hour-long standoff and passed food into the home through an upstairs window, state police Col. Rick Fuentes said.

Officers stormed the home at around 3:45 a.m. Sunday after noting Murphy's "deteriorating state of mind" and deciding it was necessary to enter to help ensure the captives survived, Fuentes said. An officer shot Murphy because he was threatening one of the children, he said.

Murphy was taken to a hospital and later died of his injuries.

Authorities found the bodies of 44-year-old Carmelita Stevens and her teenage son in separate bedrooms. The woman's body was in an advanced state of decomposition, and police said she appeared to have died two weeks ago.

Three of her children — an 18-year-old woman, a 16-year-old girl and a 4-year-old boy — were rescued and taken to a medical center for evaluation and treatment. Murphy had abused and assaulted the captives, Bocchini said.

Murphy and Stevens had been dating for a few months, and both lived in the house, police said. He was not the father of any of her children.

Authorities wouldn't comment on a possible motive or say how the victims died, citing the ongoing investigation.

Murphy was a registered sex offender with a long criminal history including convictions for aggravated assault and criminal conspiracy, Bocchini said. He had previously been arrested for robbery and weapons offenses and child endangerment. He also had an arrest warrant in Pennsylvania for failing to register as a sex offender.