The family says Tran was outside of their Garden Grove home when police arrived. Witnesses say Tran was following orders from police when he was suddenly shot with a Taser gun.
"He lie down on the grass, police tell him get up. He just got electric ... boom, boom ... my son die," said Tran's father.
The Tran family says they had called for an ambulance in the past, to help get Tran to the hospital. However, they claim he was not violent.
"He's very quiet. He had mental problems where he didn't interact that much with everybody," said Thanh Truong, the victim's brother-in-law.
"He has a long history of mental illness and also had a prior arrest of under the influence of illegal drugs," said Lieutenant Dennis Ellsworth, Garden Grove Police Department.
Garden Grove police say they arrived to find Tran trying to get in through a window of his parent's house. Police say they tried to handcuff him.
"A struggle ensued. One officer then deployed the Taser, which struck the subject in the leg. They were able to then handcuff the subject on the ground," said Lt. Ellsworth.
The Taser is considered a "less-than-lethal" weapon used to temporarily incapacitate someone. Every Garden Grove police officer carries one.
"This is the first time we ever had a Taser deployed where someone has died. We don't know if that had anything to do with it and it obviously will have to go through our investigation through the police department," said Lt. Ellsworth.
The use of Tasers is controversial. Amnesty International claimed that in 2007, nearly 300 deaths were indirectly linked to Taser use worldwide.
However, for the Tran family, they continue to question what happened.
"He didn't resist arrest, but they're still questioning why he was Tasered," said Truong.
Police say after Tran was Tasered, they called paramedics. They say they noticed he was not breathing.
He was pronounced dead at the hospital and authorities are awaiting autopsy results.
It is standard procedure for the Orange County District Attorney's office to conduct an independent investigation within custody deaths like this.
According to another 2007 study, out of 1,000 cases where police used Taser guns to subdue suspects, 99.7 percent suffered no injuries or minor injuries. Also according to that study, two people died, but through autopsies it was revealed that they did not die as a result of Taser gun use.