An official at the Worcester funeral home, where the suspect's body is being held, said his death certificate cites "gunshot wounds of torso and extremities."
Tamerlan Tsarnaev's body was released to the funeral home Thursday. He died last month after a gunfight with authorities. Police have said he ran out of ammunition before his younger brother, Dzhokhar, dragged his body under a vehicle while fleeing the scene.
Investigators continue to probe female DNA found on the remains of one of the two bombs set off near the finish line of the Boston Marathon April 15. So far, the DNA does not match that of Tamerlan's wife, Katherine Russell, sources told ABC News Friday.
Investigators do not know if the DNA came from a victim in the attack, from someone who handled the bomb components before it was constructed or from a possible co-conspirator.
An attorney for Russell said in a statement earlier this week that Russell was providing "as much assistance to the investigation as she can." The attorney also said Russell had no prior knowledge of the plot.
The twin blasts killed three people, including an 8-year-old boy, and injured more than 260 others.
ABC News sources also revealed Thursday that Dzhokhar told investigators that he and his brother originally planned a Fourth of July attack in Boston. They changed course once they realized they had developed working explosives sooner than expected.
ABC News and the Associated Press contributed to this report.