Gallo is charged with three counts of second-degree murder and a count of felony hit-and-run in the deaths of Adenhart and his two friends, Courtney Stewart, 20, and Henry Pearson, 25. A fourth passenger, Jon Wilhite, was critically injured in the crash but survived.
Police said Gallo, 23, was driving drunk. His blood alcohol was nearly three times the legal limit when he allegedly ran a red light at a high rate of speed and slammed into the victim's car.
Prosecutors charged Gallo with second-degree murder because he had a prior drunk driving conviction and was driving with a suspended license.
Goodman said her client is facing the more severe charge of murder because of the publicity surrounding the case and Adenhart's fame. However, the prosecutor told jurors in her opening statement that the facts clearly warrant the charges and a conviction.
The judge in the case has rejected repeated requests by the defense to try to move the trial out of Orange County due to the publicity of this case and also due to the fact that Adenhart was a well-known Angels player.
If convicted, Gallo could face more than 50 years in jail.
The Angels organization declined to comment before the trial for fear of influencing the proceedings.
Some of Adenhart's former teammates, however, said his death has left a void both on the field and in the locker room.
The Associated Press contributed to this report.
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