Police said that the masked thugs zip-tied Sullivan's relatives - including the little girl - and gagged them with duct tape while they raided the house, stealing cash. Police said Thursday that they were unsure how much money or if anything else was taken from the house.
Sullivan's 22-year-old brother was hit in the face and suffered a cut during the attack, but his young niece, 30-year-old sister and his mother, who police said is in her 50s, were not physically harmed, investigators said.
In the immediate aftermath of the crime, gut-wrenching wails of relatives and friends who gathered on nearby stoops and corners filled the narrow block, echoing off the houses as police led the traumatized victims - Sullivan's sister's arms wrapped tightly around the child - onto the stoop of the two-story brick house.
Cops quickly whisked them away to be interviewed by homicide detectives. Investigators said they didn't think that anyone saw the gunmen enter or leave the house. But a surveillance camera mounted onto the awning of a nearby corner store may have filmed the men.
Small said that the victims told police that three to five men, all wearing masks, were involved. He said the duct tape and zip ties were found in the bedroom where Sullivan was slain and in the living room. A shell casing also was found in the bedroom.
Investigators Thursday were unsure whether there were any signs of forced entry, and police said that they're not sure if the victims knew their attackers.
Sullivan was convicted last year on an animal-cruelty charge for clipping two puppies' ears and was fined, the PSPCA said.
Early Thursday, as police continued to investigate the crime, disbelieving relatives held each other tightly, tears flowing.
A man who gave his name only as Cary and identified himself as Sullivan's cousin looked on with a crowd of about 30 people - most of whom, he said, were other family members - who gathered at the end of the block.
"Right now, we're just trying to find out what happened," he said. "We're hurting."
Contact Morgan Zalot at 215-854-5928 or firstname.lastname@example.org, or follow on Twitter @morganzalot. Read her blog: phillyconfidential.com.