The Philadelphia Inquirer, citing sources in law enforcement, said the brothers had spent $100,000 given them to buy drugs at a casino in the Philadelphia suburbs. A third man, who survived, was a friend called by one of the brothers after the gang abducted them and demanded their money back, investigators said.
The survivor was found early Wednesday on the riverbank in his underwear, hands and feet bound with duct tape. He had been stabbed seven times.
The bodies of the brothers were found in the river, also bound with tape and weighted down.
"It's one of the more barbaric murders that I've seen," Clark said. "It's very brutal. All of them, their hands and feet were bound, their eyes were covered, they were stabbed multiple times . . . and then thrown into the Schuylkill."
Police searched a house Thursday where investigators believe they were held. They found pieces of duct tape with what appeared to be blood and a bucket like those used to weigh the bodies down.
Clark said all three victims were "well-known to police."
Investigators said the survivor, after getting a call from one of the brothers, brought $40,000 to the house.