A B.C. man accused of sexually assaulting a young woman during a violent break-in at her uncle's house has been found guilty, even though his brother took the stand to take the blame.

Justin Derek Rao was charged with break and enter, unlawful confinement, sexual assault and robbery after a break-in at 6513 Clinton Street in Burnaby in the early hours of Dec. 7, 2008.

B.C. Supreme Court heard that Rao was one of four men who stole laptops, cell phones and cash from the home while holding a man, his son and two nieces against their will with threats of violence. The elder of the nieces, then 24, was held down, beaten and raped by three men.

Rao's DNA was found on the rape victim's t-shirt, body and fingernails, and she told police that a dark-skinned man matching his description hit her, choked her and threatened to kill her before forcing her to perform oral sex multiple times.

During the course of his trial, Rao called only one witness: his older brother, Daniel Vicky Rao.

The elder Rao testified that he also participated in the break-in and said that he was the one who forced the young woman to perform oral sex on him while another man raped her. He even went so far as to say that Justin Rao walked into the room, saw the assault in progress, and demanded, "This is not like us, what the hell are you doing? Let's get out of here."

The analyst who examined the DNA conceded to the court that she could not exclude Daniel Rao as the source of the sample on the victim's t-shirt or body, but the DNA in the nail clippings was undeniably Justin Rao's.

And Daniel Rao's description of what happened that night didn't match up with anyone else's, including the victims'. No one else reported seeing two dark-skinned men involved in the break-in.

The judge hearing the case, Justice Mary Humphries, said she did not believe Daniel Rao was involved in the crime at all.

"Daniel Vicky Rao's evidence is not credible, either when taken in the context of all of the evidence, or even on its own. His demeanour in the witness box was off- hand and careless," Humphries wrote in a decision Tuesday.

"Taking all of the evidence into consideration, Daniel Vicky Rao's testimony is not believable, nor does it raise a reasonable doubt."

She found Justin Rao guilty on all four counts; he has yet to be sentenced.

Another man, Jason MacFadden, was also indicted in the violent break-in and rape, but he pleaded guilty to sex assault and break and enter on the first day of his trial.