DALLAS, Ga. (AP) - Police are guarding the Georgia home of a couple accused of child cruelty after a teenage boy weighing just 87 pounds was found wandering a Los Angeles bus station.

Investigators are planning to search the home, where authorities say the boy was kept in such isolation that his two sisters in the same house did not know what he looked like, Paulding County sheriff's Cpl. Ashley Henson said Friday.

"The sisters haven't seen the brother in over two years," Henson said. "They didn't even know what color his hair was."

Paul and Sheila Comer face charges of false imprisonment and cruelty to children, Paulding County jail records show. They're being held without bond. The records do not indicate whether the Comers have an attorney.

The FBI and the Georgia Bureau of Investigation have joined the case, Henson said.

Mitch Comer told police his stepfather gave him $200 and a list of homeless shelters before he was put on a bus to Los Angeles on this 18th birthday, police in Los Angles said Thursday.

Retired Los Angeles police Sgt. Joe Gonzalez was working security at a downtown bus station Sept. 11 when he spotted the teenage boy, who stood just over 5 feet tall and looked much younger, Los Angeles police said in a statement Thursday.

The boy told Gonzalez his stepfather declared that he was now a man before putting the teen on a bus.

Because he was so childlike, police worried that he wasn't as old as he claimed and decided to investigate further. The teen told authorities he had suffered years of abuse after being taken out of school in the eighth grade.

"There's really no indication right now as to why these parents did this to these kids," Henson said. "This is a new one on a lot of folks... this is just horrific."