Lavonte Drummer and Dominic Davis, both of Oakland, face murder charges in connection with the beating and made their first court appearance on Thursday afternoon in Oakland.
Their families and friends were in court.
"This is a tragedy on both sides. These young men I'm sure didn't mean to kill this man," Maryo Lions said.
Outraged members of Oakland's Chinese community were also in the courthouse, along with Tian Sheng Yu's widow and son, 27-year-old son, Jin Cheng Yu, still bruised from the attack. And they had a message.
"The true justice, true justice is no more violence to anyone, any family," the widow said through translator Carl Chan from the Oakland Chinatown Chamber of Commerce. "They are very sad. They lost a husband and a father and we all know how difficult it is."
After nearly four days in grave condition following the Friday afternoon attack in Oakland's Uptown neighborhood, family members on Tuesday decided to disconnect life support for 59-year-old Tian Sheng Yu. The documents released on Thursday show he died of head trauma after the blows knocked him to the ground.
Due to the tension stirred by the attack, Oakland police chief Anthony Batts made a rare appearance for the first hearing.
"I think there is a lot of sensitivity in the community about this event. I wanted to be here in support," he said.
The attack was captured on video and though authorities have not released it, Chief Deputy District Attorney Tom Rogers told ABC7 News it shows Drummer punch Yu in the face and then "a split second later, punching Yu in the face."
The blows knocked Yu to the concrete where he hit his head, and "laid in a pool of blood," Rogers said.
Rogers said Drummer told investigators "he had some frustrations in his personal life. He shared that with Davis and they both agreed they would hurt someone."
Oakland police say the two men first sucker punched Cheng Yu. They then attacked the father when, speaking Chinese, he asked for a reason for the attack.
Rogers said no words were ever exchanged and that there's no evidence of a hate crime. The case has ignited racial tensions in Oakland because the suspects are black and the victims are Asian.
The motive doesn't surprise community activists in Oakland.
"This is symptomatic of what we're seeing in Oakland in the last few years, where young people have nothing to do, there are no jobs available, they're becoming more and more hopeless, and more and more angry," said Debra Snow for Oakland Community Organizations.
Rogers said the two young men have extensive criminal records as juveniles.
Drummer was charged in 2009 with felony battery for attacking a 55-year-old black man in a convenience store and Drummer and Davis also were arrested in 2007 for the strong arm robbery of a white man. Rogers said neither was charged in the case and they were released to their parents. Last August, Drummer was found guilty of possessing ammunition for a .22 caliber gun.
Two months ago, on Valentine's Day at 4:00 a.m., police showed up at an apartment complex where the mother of Drummer's baby lives. According to investigators, Drummer slapped the woman across the face because she had a new boyfriend.
Both suspects are due back in court on Friday.