Kilani DeRego, 19, accused of beating a taxi driver to death took the stand in his defense on Thursday.
On the stand, DeRego said he was with his girlfriend at a friend's apartment on Schofield Barracks the night of May 1, 2010, when taxi driver Charlys Tang, 41, was found beaten to death in a Waipahu parking lot.
DeRego's girlfriend and two friends testified earlier that DeRego was with them that night.
The defense presented DeRego's Facebook page as evidence he was not in a taxi with friend Michael Robles.
In a post at 11:33 p.m May 1, DeRego wrote: "In Wahiawa about to go to sleep. Good night FB. I love you babe. See you in the morning."
Michael Robles, 19, was sentenced last October to 20 years in prison for Tang's death.
During his trial, Robles claimed he only played a minor role in the beating and that DeRego delivered the fatal blow. DeRego denies the accusation.
DeRego testified he had left with permission from the Hale Kipa group home in Manoa where he was a client, and went to his father's house and was hanging out with his friends and girlfriend the weekend of the beating.
But he testified when police caught him in Waikiki days after Tang's death, he thought he was being arrested for being a runaway.
"I said, 'swear to God I wasn't there, I was with my girlfriend that night,'" DeRego said he told police. "It's the truth."
Prosecutors put Robles on the stand earlier in the trial, but Robles pleaded the fifth for his entire testimony.
Closing arguments are expected Friday.