"There's just overwhelming sorrow and a desire to find some way to help these children. ... There's no place for anger anymore," said Tom Grilk, 52, who knew Michael Costin, a single father of four, because Grilk had coached one of Costin's children in hockey.
Grilk had brought his 10-year-old twin sons to the funeral at Our Lady of Assumption Church "for them to be part of this time and show support for the family and, in some small way, to understand the horror of anger gone wrong."
Joan Donovan, a teacher from Lynn, said, "For God's sakes, what a parent will do in anger!"
"It's the children who really lost here," she said.
Costin, 40, of Lynnfield, died after being beaten unconscious in front of children, some as young as 10. He had recently won custody of all his children.
At a wake Monday, one of Costin's sons was so overcome with grief that he crawled into his father's casket.
Thomas Junta, 42, of Reading, was released on $5,000 cash bail Monday after pleading innocent to manslaughter in Costin's death.
Junta's lawyer said his client was acting in self-defense, and that the victim started the fight. Prosecutors say Junta was charged in 1992 with assault and battery. There was no finding in the case.
If convicted, Junta faces a possible sentence of up to 20 years' imprisonment.
Authorities had sought $25,000 cash bail, but the judge agreed to a lesser sum because of Junta's clean record and ties to the community. A truck driver for 13 years, Junta has a son, 10, and a daughter, 16.
An autopsy showed Costin was brain dead almost immediately after the fight Wednesday night. He was pronounced dead two days later after being taken off a ventilator.
By all accounts, the fight started over rough play during an informal stick practice at the Burbank Ice Arena in Reading, a town 15 miles north of Boston.
According to witnesses, Junta became very upset when one of Costin's sons allegedly shoved his son. Junta then is alleged to have attacked Costin off the ice at the skating rink. He was escorted outside, but he came back later and went after Costin again.
"Let's hope this sends a message out to the whole country, not just Reading, that this could happen to anybody," said Augustine Costin, father of the slain man who died Thursday.
The victim was a single father of four kids, and his children saw the attack.
"My grandson was holding my son's head and said, 'Stop hitting, stop hitting. Wake up, daddy. Wake up, daddy. Please wake up,'" said Augustine.
The medical examiner has ruled the manner of death a homicide. The cause of death was blunt force drama to the head and neck of the victim, according to The Middlesex County district attorney's office.
Junta is 6'1" and 275 pounds. Costin, the victim, was 6'0" and 150 pounds.
Fred Engh, author of Why Johnny Hates Sports, and the founder of the National Alliance for Youth Sports, a group that teaches parents how to behave at children's sporting events, told CBS News this case should serve as a wake-up call for parents across America.
"This is the first death we've heard about but violence in sports for children is a growing thing and the bottom line is, we have to put an end to it."
Parents must show restraint, said Engh.
"It's a terrible thing we're doing to children When they see this kind of violence across this country, they think it's acceptable," said Engh.
Junta was a model suburban father, according to his neighbors. Engh explains what could cause someone to fly off in a rage like this.
"We look around this country and we see road rage. We see airport rage. Now we see youth sport rage where parents are out on the field and they have no control. They've lost perspective. They don't understand that these are growing children that are developing character traits that will carry on for a lifetime. That's why it's so important."
Ed Marchand, chief of the Reading, Mass., police department, told CBS News Junta gave a full statement to detectives the night of the incident, Wednesday, July 5.
"He claims that there was an altercation earlier, and he claims that the victim struck him, and he was actually escorted out, told to leave the rink," said Marchand. "He come back inside and they went right at it, and he landed on top of the victim and then was punching him."
According to Marchand, the men didn't know each other.
State Criminal Registry records showed Costin was arraigned 36 times between 1979 and 1995 on charges ranging from assault and battery on a police officer, to illegal gun possession to violation of restraining orders.
He was sent to prison seven times between 1983 and 1995, serving anywhere from 30 days to 15 months each time.