The family of a 15-year-old killed early Saturday in Denver is mourning their son and trying to find answers. A cousin who was with their son when he died says the attack on the two came without warning. 

The 18-year-old cousin told the family that he and Demetrius Cruz were heading home after a night out when a white car began chasing them, bumping the rear of their vehicle repeatedly as they fled.

The Denver Post is not publishing the name of the cousin because he is a witness to the crime and the suspects are still at-large.

Before the incident ended in southwest Denver, someone in the white car opened fire, killing Demetrius Cruz. Cruz died of two bullet wounds to the back, according to the Denver coroner's office.

Denver police have released few details about the shooting that occurred about 3:50 a.m. Saturday.

The older cousin was driving when they were attacked, said Demetrius' mother, Antoinette Cruz, 35.

Demetrius, whose nickname was "Meech," called an aunt during the chase that began near Lowell Boulevard and Irving Street and ended at Sheridan Boulevard, between West Dartmouth and West Bates avenues.

"My son was scared. He called his aunt and told her that they are chasing us, they keep hitting the car,.' " said Demetrius' father, Sonny Cruz, 39.

Demetrius Cruz had planned to spend the night with his cousin, at the home of the cousin's great-grandmother.

In an interview Monday she said Cruz' cousin told her that bullets were hitting the car as he drove. "He said he didn't know how he was driving. He was ducking down." She is not being identified to protect the cousin.

The cousin carried Cruz' s body as he pounded on doors in the neighborhood trying to get help.

When police responded, Cruz was taken to Denver Health Medical Center, where he was pronounced dead.

Sonny and Antoinette Cruz have been living in a Volunteers of America homeless shelter.

"He was staying here, but he wanted to spend the night with his cousin," Sonny Cruz said of his son.

He added: "He is a funny kid, he is a jokester. He can walk in the room and make people laugh."

Antoinette Cruz said she feels for families of those killed in last week's Newtown, Conn. massacre. "My son got killed with a gun," she said.

Tom McGhee: 303-954-1671, tmcghee@denverpost.com or twitter.com/dpmcghee