Police discovered the bodies after responding to a car crash about a half-mile from the house, Northampton County District Attorney John Morganelli said. The driver was covered in so much blood that police knew it wasn't all from the car crash, Morganelli said.
The driver's statements led officers to the house, Morganelli said, declining to elaborate. Three bodies were found on the first level of the home; the fourth was in the basement, he said. All were stabbed multiple times.
"It's a very bloody crime scene," Morganelli said. "I've been DA 18 years and I've never seen anything like this in my life."
The names of the victims and the suspect were not immediately released. The suspect was being treated at a hospital for non-life-threatening injuries believed to have occurred during the car crash, Morganelli said. Charges were pending.
Authorities were still trying to identify a motive for the stabbings, the prosecutor said.
State police were investigating.
One of the victims appears to have had a relationship with the suspect, Morganelli said. He identified another as a next-door neighbor.
"He heard screams and commotion," Morganelli said. "He went over to help and became a victim."
Other neighbors on the tree-lined street full of large brick homes said they heard sirens around 4:30 p.m.
Hours after the bodies were discovered, the block remained roped off. Several people milling around the street in Northampton, a town of around 9,500 people about 70 miles north of Philadelphia, described it as a quiet neighborhood.
"It's so strange to have it happen here," said Lee Danbar, 37, who grew up in the area and lives a couple of blocks away. "It was always a safe area."
