Prosecutor Elgin Lowe alleged that Daniel Howard, a 31-year-old trucker from Fremont, was one of two people who fatally stabbed Afoa near the intersection of Cedar Boulevard and Birch Street in Newark at about 3:30 p.m. on Dec. 15, 2010.
Afoa was a defensive lineman at Newark Memorial High School and made second team all-league in the Mission Valley Athletic League in the 2009 season.
In addition to convicting Howard of murdering Afoa, jurors found that Howard committed the crime to benefit a criminal street gang.
Howard also was convicted of two counts of premeditated attempted murder for trying to kill his girlfriend and her unborn child in a separate incident in Fremont on Nov. 25, 2012.
Rafael Tovar, a 32-year-old batch mixer from Newark, and Tovar's sister Daniela Guzman, 19, of Newark, also are charged with murder in connection with Afoa's death but they are scheduled to be prosecuted in a separate trial at a later date.
Newark police spokesman Mike Carroll said Afoa transferred to Bridgepoint Continuation High School in the fall of 2010 but after school he regularly walked to Newark Memorial High School, where he would work out and meet with his friends there.
Carroll said the location where Afoa was killed is only a short distance from the school.
According to a probable cause statement filed in court by Newark police Officer Dan Anderson, the event that sparked the chain of events that led to Afoa's death was when Afoa beat up Tovar at Tovar's home at 12:28 a.m. on Sept. 12, 2010.
Tovar was so badly beaten up by Afoa that he eventually had to be taken to Eden Medical Center in Castro Valley for treatment, Anderson said.
Tovar later learned that Afoa had been bragging about beating him up and Tovar felt "great embarrassment" because he was a member of the Norteno gang and was much older than Afoa, according to Anderson.
On Oct. 30, six weeks after the first incident, Tovar plotted to attack Afoa at a party at 36187 Cedar Blvd. in Newark, Anderson said.
Afoa was assaulted with a beer bottle and a friend of his suffered "numerous severe stab wounds" but no arrests were made because the people involved in the incident were uncooperative with police, according to Anderson.
The officer said that when Afoa visited his friend in the hospital, where he was being treated for his stab wounds, Tovar confronted him and "told him he would get his."
Guzman later admitted that she had set up Afoa to be assaulted at the party in retaliation for the beating of Tovar, her brother, although she refused to disclose who the assailants were, according to Anderson.
Anderson said Tovar eventually admitted that he stabbed Afoa about five times on Dec. 15, 2010, and estimated that Howard also stabbed Afoa about five times.
Lowe said the chain events that led to Afoa's death also led to the stabbing death of his friend, 18-year-old Newark Memorial High School football star Osana Futi, in Fremont in April 2012.
Lowe said 19-year-old Abraham Hade of Fremont, whom he alleged was a leader of a branch of the Norteno gang called Fremont Mexican Territory, killed Futi because Futi had quarreled with the gang's members because he believed they were responsible for Afoa's death.
No one had been charged in connection with Afoa's death when Futi was fatally stabbed 13 months ago, as Howard, Tovar and Guzman weren't arrested and charged until last December.
Hade was convicted of second-degree murder for Futi's death and was sentenced today to 16 years to life in state prison.
Howard's attorney, Darryl Stallworth, said he's "disappointed" with the jury's verdict against Howard because he believes there was insufficient evidence to prove that Howard was present when Futi was killed and was one of the people who stabbed him.
Stallworth said two witnesses testified that Futi was stabbed by two Hispanic males and he argued to jurors that Howard couldn't have been one of the stabbers because he's white.
Stallworth said he also believes premeditated attempted murder was too serious a charge for Howard's confrontation with his girlfriend last November.
Stallworth admitted that Howard put a rope around his girlfriend's neck but said he doesn't believe Howard really tried to kill her and her unborn child.
Howard, who also has prior convictions for assault and false imprisonment, faces life in prison when he's sentenced by Alameda County Superior Court Judge Winifred Smith on June 27.
