The children, believed held since April 24, would be rescued unharmed early Sunday when the 37-hour standoff ended amid police gunfire that killed Murphy, 38. Stevens' only other child, a son, 19, was found unharmed and hiding in the basement soon after the standoff began, police said.
"Our mission . . . was to save innocent lives," said Col. Rick Fuentes, superintendent of the New Jersey State Police. "In fact, that is what was accomplished."
For many tense hours, during which the street was blocked and residents evacuated to shelters, state and local police tried negotiating with a man Fuentes said had a "deteriorating state of mind."
Murphy, who lived for a time in Philadelphia, also had an extensive criminal history, police and court records reveal.
In February 1993, Murphy was arrested and charged with aggravated assault. A Philadelphia jury found him guilty in 1995. He was sentenced to 21/2 to 5 years in prison, according to court records.
In March 1994, Murphy pleaded guilty in Philadelphia Common Pleas Court to criminal conspiracy and theft and was sentenced to three years' probation, court records said. That sentence was later changed to a prison sentence of 6 to 23 months for unspecified reasons, court records show.
In January 2001, the 6-foot, 170-pound Murphy was arrested in Philadelphia on charges of rape, corrupting a minor, and false imprisonment, according to court records. In May of that year, Murphy pleaded guilty to a single charge of sexual assault and was sentenced to 4 to 10 years in prison, records show.
On Friday, when Murphy's standoff with police in Trenton began, he was wanted on a bench warrant for failing to register in Pennsylvania as a sex offender, police said.
On Sunday, the Pennsylvania State Police Megan's Law website showed Murphy's status as "absconded," meaning police had lost track of him. Murphy had a tattoo on his right arm of boxing gloves, a star, and his nickname, "Skip," according to the website.
Murphy had lived for the last four months with Stevens and her five children on Grand Street in Trenton, according to Mercer County Prosecutor Joseph Bocchini Jr. Authorities would not say how they believe Murphy killed Stevens and her son.
Murphy "abused and assaulted" the teenage daughters, police said.
They and their 4-year-old brother were taken to a medical center for treatment, Bocchini said. As of Sunday afternoon, the boy was "safely residing with family," Bocchini said. The girls will be placed in a family member's custody after being evaluated by the New Jersey Division of Child Protection and Permanency, Bocchini said.
Police reported to the apartment at 2:47 p.m. Friday after receiving phone calls that Stevens' two daughters had not attended school in 12 days and that a concerned family member had not heard from Stevens for a while, according to Trenton Police Director Ralph Rivera Jr. Rivera said officers made a forced entry through a rear door and smelled decomposing bodies. He said that the home was full of maggots and that Murphy had barricaded himself in a second-floor room.
Local and state police tried negotiating with Murphy for hours. State police entered the house about 3:45 a.m. Sunday, shot Murphy, and rescued the children. Murphy later died from his wounds.
He was not the father of any of Stevens' children, police said.
Contact Sulaiman Abdur-Rahman at firstname.lastname@example.org, or follow on Twitter @sabdurr.