(CNN) -- The mother of a Georgia teen beaten to death at a house party referred to her son as a "silent hero" and called for justice after the four teens accused of his murder appeared in court Monday morning.

"My son did not die in vain," said Monique Rivarde, mother of 18-year-old Bobby Maurice Tillman. "Something will be done about these children attacking each other for nothing."

Horace Damon Coleman, 19, Emanuel Benjamin Boykins, 18, Quantez Devonta Mallory, 18, and Tracen Franklin, 19, were brought into the courtroom one by one to face one count of felony murder. Police say the boys beat Tillman to death outside a party in metro Atlanta that had gotten out of control Saturday night.

Sheriff Phil Miller told CNN the attack happened after girls got into a fight, and one of the girls hit a boy. One of the suspects, according to Miller, said he wasn't going to "hit a girl," but the next guy who came by was going to get "beat down."

Tillman was the unfortunate victim, and he was a "little guy, 18 years old, 5-foot-6, weighed 125 pounds," said Miller, who added that he didn't think the boys even knew each other.

The suspect went to Douglas County High School, while Tillman went to Chapel Hill, the sheriff said.

"As a parent who is about to bury her child, you wonder why. Why didn't anyone help?" asked Rivarde.

A judge ordered no bail for the suspects until they can speak with an attorney. All but Franklin, whose mother told the judge she had already hired a lawyer for her son, asked for court-appointed counsel.

"I don't even want to think about those cowards," said Tillman's mother. "Hopefully they get life in prison for what they did."

Police arrived on the scene early Sunday. They were called by the mother of the girl who had hosted the party after it had gotten out of control. Miller said there were 60 to 80 people at the party. Fifty-seven witnesses were taken in for questioning.

After the initial hearing, the sheriff responded to criticism from parents who complained about partygoers being bused in from the party to the police station, and held without their permission.

"This is not about the sheriff's office or the inconveniences about solving a murder case," Miller said. "And that's what we did, and that's what we're proud of."

The Douglas County district attorney stood next to the victim's mother, calling the attack "an absolutely unprovoked senseless killing" of a "completely innocent victim."

"I don't think we're ever gonna learn why it happened," D.A. David McDade said.

Some family members praised officials for the way they have handled the case so far. They held up a large framed prom portrait of Tillman for reporters to see as his mother described him as a person who loved basketball.

"My son was an angel here on earth," Rivarde said solemnly, "just a good person."

No drugs or alcohol were found at the scene, according to the sheriff, and he doesn't expect any more charges in the case.

A grand jury will convene in two weeks. The suspects are expected to be indicted at that time.

CNN's Chuck Johnston and Tristan Smith contributed to this report.