LOS ANGELES - The two men accused of brutally beating a San Francisco Giants fan outside Dodger Stadium pleaded not guilty Wednesday, but prosecutors said they have made admissions in the case.

During a brief arraignment, defendants Louie Sanchez, 28, and Marvin Norwood, 30, entered their not guilty pleas to charges of mayhem, assault and battery in the March 31 beating of Bryan Stow, a Santa Cruz paramedic who suffered severe brain injuries and remains hospitalized.

In response to a motion to allow television cameras in the courtroom, prosecutor Frank Santoro said he did not object because the case was not based on witness identifications but on admissions.

"The case is based on admissions from both of them," Santoro said.

He said 20 witnesses had been asked to identify the men, but only one person was able to positively identify Sanchez and no one could identify Norwood.

"This is not an identity case, there are statements made by both defendants," Santoro said.

The camera motion was denied after the defence objected.

Outside court, Sanchez's attorney, Gilbert Quinones, was asked about the prosecutor's claim that Sanchez and Norwood had made admissions.

"Making assertions and proving them are two different things," Quinones said.

During the hearing, several family members looked on as Sanchez and Norwood stood about 10 metres apart. They did not look at each other and spoke only through their lawyers. Relatives declined to comment to the media.

Police have portrayed Sanchez as leading the assault on Stow, which came March 31 at the culmination of an alleged rampage in which Sanchez and Norwood are accused of lashing out randomly at rival Giants fans at the stadium.

Stow's family said on a website this week that he was making slight improvements and had been able to pucker his lips when his sister gave him a kiss and could lift his leg and arm slightly.