Acting Philadelphia Commissioner Christine Coulter said Maurice Louis shot his mother, step-father, and two half-brothers in the head with a shotgun. She said he was found in a bedroom in the house and surrendered to police without any issue.
"We're convinced he is the killer of the four people in the home. Extremely tragic. I don't know how you describe the killing of four people, let alone to discovering it was done by somebody in their own family," Coulter said.
Officers responded to the home on the 5000 block of Walton Avenue at about 12:40 p.m. Wednesday to check on the well-being of a couple that did not show up for work.
"The employer of the male and female that resides here notified police that their employees did not show up for work, which is very unlike them," said Deputy Commissioner Joe Sullivan with the Philadelphia Police Department.
Sullivan said police used a firetruck to gain access to the second floor of the home.
"A ladder truck granted us access to the second floor. Officers from the 18th District went inside. Once inside, they did encounter the suspect. He notified them that there were dead bodies," said Sullivan.
When officers arrived, they found four shooting victims: a 52-year-old woman by the front door, an 18-year-old boy in a bedroom, a 7-year-old boy in the kitchen and a 56-year-old man by the basement door.
All four were pronounced dead by a medical unit.
Family members have identified the victims as: Janet Woodson Holmes, 52, Leslie Holmes, 56, Sy-eed Woodson, 18, and Leslie Holmes Jr., 7.
Reggie Woodson, Janet's older brother, watched in disbelief behind the maze of crime scene tape.
"I'm so numb. I can't even express what I feel now," said Reggie Woodson.
Detectives say the suspect, Maurice Louis, is the son of Janet Woodson Holmes.
Relatives said he suffered from depression and had been clinically diagnosed. Commissioner Coulter, however, said she has not seen any medical records indicating any mental issues.
"Stuff like that you would never think would happen, and my sister she treated him, gave him everything," said Reggie Woodson.
It's not clear when exactly the murder took place, nor what prompted the carnage on this quiet block.
Relatives say the family had just returned from vacation at Disney World.
Janet was an entrepreneur, running a hair salon out of her home.
Leslie Jr. attended Discovery Charter, and Sy-eed was a senior at Boys Latin, who just started applying for colleges.
The couple had been married for nearly two years, tying the knot on Easter in their home with family and friends.
City officials will be at both the schools of Sy-eed Woodson and Leslie Holmes Jr. to help with counseling.