Four people were found "executed" in the basement of a Philadelphia home, authorities said Monday.
The victims who were shot dead were two men and two women who appeared to be in their 30s, Philadelphia Police Commissioner Richard Ross Jr. said at a Monday news conference. It appeared they were shot in the head on Sunday night.
"Sadly, all four of these individuals were executed," Ross said, calling it an "evil" act and a "horrible scene."
(MORE: Despite renewed calls, funding for research on gun violence continues to stall)The home appeared to be in the process of being renovated, Ross said, and when a neighbor heard banging Sunday night, he thought it was part of the renovations.
It appeared the victims were led to the basement, Ross said, citing that there were no signs of struggle in the home.
(MORE: 'I hope... before my time on Earth is gone that I have those answers': Victim's sister on 1978 unsolved quadruple killing)At least one of the victims lived in the home, police said, and some of the victims may be related.
"This could be anybody's family," Ross said. "You just hope that people don't get desensitized to these horrible acts that just keep occurring."
(MORE: Suspect in 2015 quadruple murder in Washington, DC mansion convicted of 20 counts, including murder, kidnapping)There's no indication of motive, Ross said.
"We're interviewing witnesses, family members to see if we can determine what this might be about, as well as checking potential surveillance cameras in the area," Ross said.
The area is gentrifying, Ross said, adding that this block isn't frequented by police.
Ross urged anyone with information to "please call so we can get this killer off the street. Or killers."