The hearing at Men's Central Jail was being conducted behind closed doors, but Los Angeles County Sheriff's Department spokeswoman Nicole Nishida confirmed it had begun.
Giovanni Ramirez, 31, has not been charged in the attack on Bryan Stow and police have been in no hurry to present a case to prosecutors while Ramirez, a convicted felon, has been kept in jail on a parole hold. Police say they found a gun in a laundry basket at the house where he was arrested.
Ramirez's lawyers say their client was nowhere near Dodger Stadium at the time of the March 31 attack.
Attorney Jose Romero has said 11 family members and friends have provided an alibi for Ramirez, saying he was at an aunt's house. Neighbors are also supporting the claim, Romero said.
If the official leading Ramirez's hearing finds there is insufficient evidence to support the claim that Ramirez was a felon in possession of a firearm, he could be ordered to be set free.
Romero said if that happened, police would likely immediately re-arrest his client to keep him in custody. Prosecutors would then only have a few days before they would have to reach a decision about whether to charge Ramirez in Stow's beating.
Ramirez's parole lawyer, J. Christopher Smith, has said he did not believe authorities had sufficient evidence to show his client was in possession of a firearm. The Police Department declined to comment.
Stow, a 42-year-old paramedic, remains in critical but stable condition under heavy sedation to prevent seizures caused by traumatic brain injury.
Police say they're still looking for a second attacker and a woman who drove the car carrying the men.
Court records show Ramirez was convicted in 2005 of possession of a firearm by a felon.
Copyright 2011 The Associated Press.