A Texas judge dealt a major blow Tuesday to the case against a man accused of filming late-night "fight club" bouts at a state facility for the developmentally disabled, ruling that videos of them could not be used at trial.

State District Judge Sandra Watts granted former employee Timothy Dixon's motion to suppress the cell phone on the grounds that it was essentially stolen property, and delayed his trial until prosecutors can appeal.

Prosecutor Doug Mann said the setback did not destroy the state's case because there will be witness testimony, but that the phone had been "the best evidence."

"The best recollection in the world will not be better than the time and date stamp on a video," Mann said.

In March, almost 20 videos dating to 2007 were discovered on the phone that was found at a clothing store and later turned in to police. The videos showed staff at the school forcing residents into fights, even kicking them to egg them on.

Eleven staff members were identified in the videos and six were charged. One pleaded guilty Monday and another has been offered immunity in exchange for her testimony. None of those charged still works at the school.

On Monday, David Herrera, who found the phone, testified that he picked it up thinking it was an iPod music player. He said he did not initially intend to search for its owner or take it to authorities. Only after taking it home and finding the videos did he decide to offer it to two television stations. When they both passed on it, Herrera's girlfriend took it to an off-duty police officer, Herrera said.

After Watts indicated Monday that she was leaning toward keeping the phone out, prosecutors flooded her with case law and argued Tuesday that the distinction was that it had been found in a public place, constituting abandonment, rather in a private place where it would have been theft.

But Watts rejected that argument, siding with Dixon's attorney Ira Miller in saying that the state had presented no evidence that Dixon had intentionally abandoned the phone. Miller declined to comment.

"This is not a popular decision and I understand that," Watts said. "I don't have any choice in this case."

Jeff Garrison-Tate of the advocacy group Community Now!, which has called for the closure of the state schools in favor of community-based services, called the judge's decision "appalling."

"It just seems like a real stretch," Garrison-Tate said. "It's unfortunate that one of the key players, or the key player, will be able to get off or at least plead it down to nothing."

Watts and Mann said the ruling should not affect the use of the videos in the trials scheduled against three other former employees, since Dixon, as the owner of the phone, was the only one with standing to make the argument that it was stolen property.

Also Tuesday, Watts scheduled the sentencing of former school employee D'Angelo Riley, 23, for Thursday. Riley pleaded guilty Monday to three counts of causing injury to a disabled person, a third-degree felony.

Trials against three other former employees are scheduled for late July and August.