OAKLAND -- A man has been arrested in connection with the beating of a severely autistic 16-year-old girl who walked away from an Oakland group home Nov. 27 and was found on a San Francisco Muni bus two days later, police said.

Police declined to release the man's name or details on the arrest because he has not yet been charged with any crimes. But law enforcement sources said the suspect is a 36-year-old man with a criminal record. . He could be charged by the Alameda County District Attorney's Office on Tuesday. Police plan to hold a news conference Tuesday to talk more about the arrest.

"I'm so glad they found this guy," said the teen's father, Jesse White. "I'm hoping this guy goes to prison for the rest of his life."

The girl walked off about 7 p.m. Nov. 27 from the Fred Finch Youth Center at 3800 Coolidge Ave. in East Oakland. She was spotted about 8 p.m. Nov. 29 on a Muni bus in San Francisco by a driver, who called police. White said his daughter has the mental capacity of a 7-year-old.

The teen was badly beaten, and family members have said she was also sexually assaulted, but police have not confirmed that. White, of Santa Maria, visited his daughter over the weekend and said it also appeared, from the severe bruising on her neck, that someone had strangled her.

"I don't know if he tried to kill her or what actually happened," White said.

He said his daughter is "stable" now and back in Washington with her mother. After initial comments, her mother has declined to speak further about the case.

The teen had been living at Fred Finch for the past 6 months, and this was the third time she had run away, her mother previously said. By law, the group home cannot be locked.

After the girl walked out Nov. 27, Fred Finch staff members followed her to the Fruitvale BART station, where they lost sight of her.

Family members said the home did not notify family members until 9:30 a.m. the next day. Fred Finch officials have declined to comment on when the family was notified.

The California Department of Social Services has opened an investigation into the incident. A spokesman there said Fred Finch had reported the runaway incident to the state, as required by law. It was not known Monday how long the state's investigation will take.

Fred Finch is a 14-bed facility for youngsters ages 12 to 18 with developmental disabilities and other issues. Teens usually receive treatment for 18 to 36 months, officials said.

Reach Harry Harris at hharris@bayareanewsgroup.com. Reach Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.