A Temple University student who was found shot to death in his off-campus apartment called 911, telling emergency dispatchers he couldn't breathe, police said Monday.

Officers found Daniel Duignam, a 21-year-old student at Temple's Fox School of Business, shot in the chest, groin and forearm shortly before 10 p.m. Saturday. He was pronounced dead at the scene.

Duignam didn't give any other information to dispatchers, said Capt. John Ryan. Emergency crews and police entered the first-floor apartment and found the gravely wounded student.

Duignam likely knew the shooter, since there was no sign of forced entry, Ryan said. The attack also bore signs of a robbery, with the apartment ransacked and money apparently taken, he said.

Police don't have any suspects yet.

"He was a good kid," Ryan said, adding Duignam had no criminal history. "Be aware who you're a doing business with and be aware of who you are inviting into your apartment."

Many students had already left for summer vacation, but Duignam had one more final exam, Duignam said.

Duignam was from Tatamy, Pennsylvania, about 55 miles (88 kilometers) north of Philadelphia. His grandfather was the mayor.

In a Facebook post, current Mayor Christopher Moren said he's "beyond heartbroken" and called the killing a "senseless tragedy."

Duignam was the sixth Temple student to die since August, a school spokesman told The Philadelphia Inquirer.

Jenna Burleigh was murdered at the beginning of the school year. Joshua Hupperterz, 29, has been accused of killing her at his home and taking her body in a storage bin to his grandmother's house in the Poconos, about 140 miles (225 kilometers) north of Philadelphia. His lawyer has said Hupperterz "didn't cause any harm" to Burleigh.

In October, Cariann Hithon, 22, was shot and killed by police in Miami in October after police said she crashed into a detective's cruiser. That same month, a 19-year-old freshman killed himself.

Two students died of drug overdoses in the weeks after Thanksgiving.

Duignam's killing was one of at least three homicides in Philadelphia over the weekend, police said.