The Georgia teenager who was randomly selected for a beating by other teens was battered and stomped so badly that one of his bones broke and pierced his heart, the coroner's office said today.
The Douglass County Coroner's office confirmed to ABC News that Bobby Tillman, 18, died of blunt force trauma.
The coroner's report said Tillman died after his heart was cut, and that it was likely cut by one of Tillman's bones breaking and slicing his heart as he was kicked, punched and stomped by four other teenagers.
The slightly built Tillman only weighed 124 pounds. He was picked for the assault at random as he passed a group of teenagers who said they intended to attack the next male they saw.
Tillman's grief stricken mother, Monique Rivarde, called her son "a child of God" Monday. She spoke shortly after the four people accused of killing him in what prosecutors said was an "absolutely unprovoked" attack made their first court appearance.
The four -- 18-year-old Emanuel Boykins, 19-year-old Horace Coleman, 18-year-old Quantez Mallory and 19-year-old Tracen Lamar Franklin -- were arraigned in Douglass County court Monday. Each was charged with murder and held without bond.
Douglas County District Attorney David McDade said he will ask a grand jury to indict the men within two weeks, but did not say whether he would pursue the death penalty.
"I don't think you'll ever know why it happened. It's senseless," he said. "This is an absolutely unprovoked, senseless killing by young people killing another young man for no reason, no motive."
According to county police, Tillman was the innocent victim of a fight between two women and two men on the street outside a party Saturday. The argument between the women and them escalated, until one of the women hit one of the men, police said.
Instead of hitting the woman back, the man said he would hit the next male who came along, according to police.
Tillman "came walking by and they beat him up and stomped and killed him," Douglas County Sheriff Phil Miller said.
Barbara Stephens, who lives across the street from the house where the party was held, told The Associated Press she saw Tillman fall to the ground and then saw one man viciously kick him repeatedly.
"I've been re-seeing it over and over," she said. "Every time I close my eyes I can see it. They were violent kicks. It was the worst thing I've ever seen."
ABC affiliate WSB-TV in Atlanta reported that members of Tillman's family broke into tears at the court hearing Monday.
Afterwards, Rivarde said of her son, "He was my best friend ... he was very loving. He was an angel here on Earth and I was blessed to be his mother."
Tillman was killed outside a house party that started out as a small gathering. According to police, the party got out of control after news of the event spread through e-mails and text messages.
Police who came to the scene loaded witnesses from the party onto a bus, a decision that caused some criticism from the local community.
"We brought 57 witnesses up here and that made some people mad," Miller said, but the sheriff insisted the move was necessary for the investigation.
Rivarde said her son was a fan of basketball.