Investigators are looking at the confessed killer of 14-year-old Ebony Nicole Dorsey in connection with the massacre of a family in Philadelphia, authorities said yesterday.

William Fowler, 53, his wife, Estella, 50, and their son, John, 20, who was quadriplegic, were fatally shot in their home in the 3200 block of Tulip Street in Port Richmond last year. No one has been arrested for the crime.

Law enforcement sources said they are now looking at Mark Patrick O'Donnell, 48, who had worked as a nurse in the Fowler home.

O'Donnell is charged with the Dec. 7 homicide of Dorsey in his apartment in Plymouth Township, Montgomery County.

"We're not allowed to say anything because there's a grand jury," said Philadelphia Homicide Lt. Philip Riehl, referring to a Philadelphia grand jury. "We're all sworn to secrecy."

On May 21, 2006, police responded to the Fowler home at 1 a.m. and found William Fowler, who made the 911 call and spoke briefly to police, shot in the head and stomach. His wife and son, both shot in the head, were pronounced dead at the scene. Fowler died at a hospital soon afterward.

Police, who found no sign of forced entry, would not disclose what Fowler said. The Fowlers required nursing care because a car accident three years earlier had left John Fowler paralyzed. In addition, Estella Fowler had multiple sclerosis and had been recently diagnosed with cancer, police said.

Surviving members of the Fowler family could not be reached for comment.

A woman answering the door at the rowhouse where the family was killed said she moved in after the incident and had no relationship with the Fowlers.

According to state records, O'Donnell received a registered nurse license in 1998. The license, which shows no disciplinary actions, was last renewed in November 2006 and expires Oct. 31, 2008.

Whitpain Township police, who are investigating the Dorsey murder, said that O'Donnell had been working as private duty nurse in West Philadelphia. Whitpain police provided no further information.

O'Donnell initially told police that he found Dorsey, who had been babysitting his daughter, changing the 4-year-old's training pants about 5:45 a.m. He said he flew into a rage, strangled her, and concealed her body in a plastic storage container outside a relative's home in Blue Bell.

The teen's mother, Danielle Cattie, said O'Donnell spent the night with her and was "wired" on crack cocaine when he left her West Ambler home about 5:30 a.m.

At his preliminary arraignment, O'Donnell said he killed the girl because she had molested his daughter. Prosecutors, who also charged O'Donnell with sexual assault and involuntary deviate sexual intercourse, said the evidence all points to O'Donnell, no one else.

Funeral services for Ebony Dorsey will be held at 11 this morning at Wissahickon High School in Ambler.

Contact staff writer Kathleen Brady Shea at 610-701-7625 or kbrady@phillynews.com.