The May 2008 crash on Sunset Blvd, killed 39 yr old Melissa Gonzales Bustamante.
Her daughter, Emily Zorrilla, testified against Isaac Soria Lopez yesterday.
The OA reports she told the jury that Lopez had gotten angry during the party, after he was accused of stealing a wallet.
Prosecutors say he intentionally hit Bustamante as he was leaving the party.
Now he faces up to 99 years in prison, if convicted.