OAKLAND -- A 25-year-old UC Berkeley graduate student was sentenced to prison for six years Wednesday for killing his girlfriend and her 6-year-old son in a horrific and tragic drunken driving accident last year.

The sentencing came after an unprecedented daylong hearing that featured more than three hours of emotional testimony highlighting the remarkable lives of Milanca Lopez, 22, her 6-year-old son, Xavier, and Jose Lumbreras, the defendant.

The testimony, which also included an almost 10-minute video tribute to Lopez and her son, had the standing room only courtroom of about 100 people in tears and almost made Alameda County Superior Court Judge Thomas Reardon break down.

The case proved tragic in part because both Lumbreras and Lopez had inspirational stories about coming out of difficult circumstances to succeed as students.

Lumbreras was the first in his family to attend college and had just graduated a master's program at UC Berkeley and was accepted into the university's doctorate program for ethnic studies.

Lopez had just graduated with a bachelor's degree and was headed to UCLA to study at her dream school's education master's program. Lopez, who was also valedictorian of her high school, had accomplished these goals despite having a child when she was 16.

More than two dozen people who spoke discussed the impact both Lopez and Lumbreras had on their lives and the promise that was taken when they ended a night of celebration drunk and driving a car with a 6 year old in the back seat.

Lopez, who was not wearing a seat belt, died at the scene of the accident at the corner of California Street and Allston Way on May 18, 2012. Her son Xavier, who was sitting in the back seat wearing a seat belt but without a car seat or booster seat, died a few days later after he was taken off life support.

Evidence showed that Lumbreras was driving his Cadillac at 65 mph along a residential street and crashed head-on into a tree. He had a blood alcohol level of at least .16 at the time of the crash, two times the legal limit. Lopez had a .11 blood alcohol level.

The couple picked up Xavier from a baby sitter just before Lumbreras crashed the car into the tree.

Lumbreras survived the crash but underwent several surgeries to repair two broken legs and various head trauma injuries. After waking from a coma and told of the deaths, Lumbreras admitted he was drunk and took responsibility.

Lumbreras also agreed to plead guilty to the charges filed against him rather than have a trial. He was charged with two counts of gross vehicular manslaughter while intoxicated.

On Tuesday, Lumbreras apologized for his actions and asked for forgiveness.

"No matter what sentence you give me, I will be punished by the realization of what I did, and I deserve it," Lumbreras said. "Please forgive me. I have made a terrible mistake. I wish every day that I could change what I did."

While the testimony Tuesday focused on the lives of those involved, it also had underpinnings of anger as it came just a month after the Lopez family filed a salacious lawsuit against Lumbreras and the university claiming the relationship between the couple was filled with abuse.

The Lopez family members urged Reardon to sentence Lumbreras to the maximum penalty allowed under law which would have been 12 years in prison.

Reardon said that it was not up to him to decide what the truth was but said after reviewing hundreds of pages of evidence detailing the couple's lives, he came to the conclusion that Lopez and her son would have forgiven Lumbreras for what he did.

At the same time, however, Reardon said Lumbreras needed to serve time for his actions.

Although Lumbreras was sentenced to six years in prison, he will be released in about two years after receiving credit for time served.

"In circumstances like this, I often say that I don't know what justice is," Reardon said. "There is absolutely no question that our world is poorer because of the loss of these individuals."