Police say the suspect stopped his car on Alder Ave, got out, and pulled the victim onto the sidewalk. Then officers say he pounded him to death.
Less than six hours into the New Year, 21-year-old Yoaddan Aguilar became a murder suspect.
Police say he beat 25-year-old Adam Rivera to death.
Rivera's father John says his son was in the wrong place at the wrong time.
"Adam was a very loving child. He was a brat in his ways sometimes, but very obedient to myself and my wife," he said.
Police say the fight started at a New Year's Eve party, probably over the suspect's girlfriend, who was seen with the victim.
Words were exchanged, and they left the party.
On the way home, they stopped on Alder Ave, near Filbert.
That's when the war of words became physical.
Police say Aguilar beat Rivera to death.
"He basically pulls the victim out of the vehicle, and starts to beat him and continues to beat him until he's helpless and he's still over the victim throwing blows," said Fontana Police Dept. Sgt. Jeff Decker.
Someone else in the car called 911 and when officers arrived, Rivera was taken to the hospital, where he was pronounced dead on arrival.
Rivera was a graduate from Colton High School. His father says he worked with those less fortunate.
"He worked with taking care of handicapped adults, that was his profession for the past five years and he really loved and enjoyed it," he said. "I'd like to remember him in those ways, not the way he died."
"This case isn't a one punch deal, this is a case of someone getting battered on the head, after he's unable to defend himself, and that's why this is a murder case," Decker said.
The DA is charging Aguilar with one count of first-degree murder.