His father had just dropped him off at Roosevelt Park in downtown San Jose when a gang of hoodlums savagely attacked Heriberto Reyes, putting the eighth-grader in a fight for his life that ended with heartbreak, police revealed Wednesday.

Heriberto, 14, died at Regional Medical Center on Monday after a massive Friday night fight on gang turf at the popular hangout spot.

Though the park was packed with witnesses, police say, most of them had scattered before officers arrived. Now authorities are desperately looking for people to come forward. No suspects in the homicide have been identified, but police say Heriberto was targeted, thought it was unclear if he had any gang affiliations.

“The murder of a 14-year-old is extremely difficult to try to come to grips with,” said Sgt. Jason Dwyer. The detectives “want what we all want: to get the people responsible for this behind bars.”

Heriberto attended Bernal Intermediate School in South San Jose and previously had attended Davis Intermediate School, both in the Oak Grove School District. The district sent a robo-call to all parents Tuesday night.

Police are revealing few details about the crime, citing the ongoing investigation. They say they waited to inform the public to give detectives time to develop leads before the assailants caught word and to allow the devastated Reyes family time to recover before their son’s death hit the news.

The encounter involving several people happened at 6:55 p.m. Friday in the park, between Julian and Santa Clara streets, just west of Highway 101, Dwyer said. After an altercation, Heriberto was beaten and taken to the hospital with severe injuries. He was pronounced dead at 2:23 p.m. Monday.

Oak Grove district Superintendent Tony Garcia said the boy’s parents dropped him off at the park, although the father apparently remained nearby. He described the assailants as a group of youths and said Heriberto suffered injuries to the head.

“In this situation, it may have been he was in the wrong place at the wrong time,” said Dennis Hawkins, president of the district’s school board.

“It could be as simple as that. I think parents are always concerned about where their kids are and what they’re doing and their safety, and to the extent that this makes us all the more vigilant about our kids, I think it’s a good thing.”

Both Hawkins and Garcia called the crime a “tragedy” and said the safety of students is their top priority. Hawkins said in his 17 years at the district, he could not remember a student being killed. The homicide was the first involving someone this young in San Jose in at least a year.

Roosevelt Park is a known gang hangout, and police said they have additional information, which they declined to release, which leads them to believe the homicide was gang-related. It’s unclear how many suspects were involved or how many people were at the park. It does not appear that any weapons were involved.

Police won’t say what Heriberto was wearing at the time or why he could have been targeted. The park and the school he attends are on opposite ends of town.

Though school officials emphasized that the attack happened off campus and while school was out, they said they will provide assistance, such as counseling, to parents, students and teachers.

The city’s 13th homicide of 2012, and the fifth that was gang-related, comes during a violent stretch in San Jose. There were three homicides, seven stabbings and one nonfatal shooting from Friday night through Monday. In one of the homicides, a shooting, an 18-year-old died Saturday night in the back of Lowell Elementary School, which produced another robo-call to alert parents.

Police fear even more violence this weekend with the annual Cinco de Mayo festivities, which kick off a summer season that traditionally brings a spike in crime with it.

Anyone with information is asked to call Detectives Stewart Davies or Brian Spears at 408-277-5283.

Staff writer Mark Gomez contributed to this report. Contact Mike Rosenberg at 408-920-5705. Follow him at Twitter.com/rosenberg17.