Three defendants accused of savagely beating and starving a teenager who was held in chains in a Northern California home for more than a year pleaded guilty Friday in a deal intended to send them each to prison for 30 or more years.

Michael Schumacher, his wife Kelly Layne Lau and the 16-year-old victim's then-legal guardian Caren Ramirez entered their pleas in San Joaquin County Superior Court to more than a dozen felonies, including use of a deadly weapon and causing great bodily injury to a child.

As part of the plea agreement, prosecutors withdrew a charge of torture, which could have led to life in prison for the three.

"We were always prepared to go to trial against the four," prosecutor Angela Hayes said. "I am certainly pleased we have come to some sort of resolution."

A fourth defendant, Anthony Waiters, the couple's neighbor, has pleaded not guilty. Jury selection for his trial on aggravated mayhem, torture and false imprisonment charges is set to begin next week.

Prosecutors said Ramirez brought the teenager to live in the home of Schumacher and Lau in Tracy in January 2008. The boy escaped the following December by unlocking an ankle chain and stumbling into a nearby fitness center bruised, emaciated and still wearing a shackle on his leg.

Under terms of the plea deals, Schumacher could face 30 years in prison, Lau 33 years, and Ramirez 34 years when they're sentenced on Dec. 6, according to court spokeswoman Stephanie Bohrer.

Hayes said the plea deal means the victim, who is now 18, will only have to answer questions from one defense lawyer instead of four during the upcoming trial.

"It would have been mentally and physically draining," Hayes said.

Calls to the defendants' lawyers were not immediately returned.

The pleas avoided a trial for the three following a March 2009 grand jury indictment.

The boy told the grand jury he endured frequent beatings — sometimes in front of the couple's young children — that worsened over the year. He testified his abusers often had conversations in front him about torturing and killing him.

The boy said Ramirez and Lau, a Girl Scout leader, beat him for such things as forgetting to water the lawn or not cleaning the bathroom properly, according to transcripts of the testimony.

He said the abusers initially hit him with their hands then eventually escalated to belts, a mallet, hammer and aluminum baseball bat. Even a razor was used on occasion.

"I remember they said they would try to, like cut me up and everything and throw me in the delta, and one time he, Michael, asked Kelly for a syringe so he could, like, pump air into my veins and stuff like that," the teen told the grand jury.

The teen also alleged he was forced to drink alcohol and eat marijuana and that Waiters once sliced his arm with a knife while Ramirez held him down and Lau watched.

"They just told me to shut up." the boy said.

(This version CORRECTS Recasts lede. Corrects to say prosecutors wiithdrew charge of torture instead of defendants pleaded guilty to that charge.)