Two men killed in this week's execution-style quadruple homicide in West Philadelphia considered each other stepbrothers and recently moved into the rowhouse where they were found slain in the basement alongside two women, a relative of one of the men said Wednesday.

Greg Brinkley, 59, of East Falls, said that a guardian for his great-nephew Maurice Taylor, 31, had recently purchased the home on the 5100 block of Malcolm Street on Taylor's behalf, using money from a long-ago civil lawsuit related to Taylor's near-drowning in a swimming pool at a Philadelphia apartment complex. Akeen Mattox, 28, also was living there and helping to renovate the property, Brinkley said.

Taylor's childhood accident caused lasting brain damage, and his relatives were "in shock" that he was shot dead in his own home, Brinkley said.

"Maurice wasn't the type to have somebody out to get him," said Taylor's cousin James Cade, 27, of Olney, who added: "He didn't want that disability to control his life. He lived a regular life. He was happy."

Philadelphia Police declined Wednesday to offer new details about their investigation, or even confirm the victims' names. Homicide Lt. Norman Davenport said that investigators had not yet made contact with relatives of one of the slain women, and that police would not release identities until family members of each victim had been notified.

Taylor's relatives said they did not know the women's identities, and police have not divulged their connection to Taylor or Mattox.

Attempts to reach Mattox's relatives this week were unsuccessful.

Davenport said in an interview that detectives were seeking surveillance video from around the crime scene and probing the backgrounds of the victims for potential clues, as is routine in murder investigations.

Police discovered the four bodies Monday after a relative called to check on the welfare of people who lived there. Each of the victims was declared dead at 12:21 p.m.

Commissioner Richard Ross, addressing reporters at the scene Monday, said that investigators were not certain how long the bodies had been in the basement, but that a neighbor reported hearing a few "bangs" around 10 or 11 p.m. the night before. The neighbor initially believed the noises related to ongoing renovations inside the home, Ross said.

The commissioner said that there were no obvious signs of a struggle or robbery, and that it appeared the victims had been led to the basement because they had not been bound, tied up, or appearing to have other injuries.

Police do not believe the crime was random, but Davenport said a motive was not yet clear. He declined to say whether police were searching for one or more gunmen, or how many shell casings, if any, were found.

Mattox had a number of recent arrests, according to court records, but it was not clear whether they had any connection to the killings. His most recent conviction was in 2016, when he pleaded guilty to burglary and was sentenced to nine-to-23 months in prison, the records show.

Cade, Taylor's cousin, said he had communicated with Taylor on Instagram on Saturday, and was looking forward to seeing him for Thanksgiving.

"To lose him," Cade said of his cousin, "everybody's life is going to be different now."