Updated at 2:47 p.m. ET
PHILADELPHIA - A fourth person was arrested Wednesday in a scheme in which authorities said mentally disabled adults were locked up in a fetid basement while their captors cashed their Social Security checks. The latest suspect was the daughter of the alleged ringleader, officials said.
Also Wednesday, an FBI official said the case could fall under the Matthew Shepard and James Byrd Jr. Hate Crimes Prevention Act, which would make it one of the first prosecuted under the 2009 federal hate-crimes law.
The act is named for two murder victims and expands an earlier hate-crimes law to include a victim's sexual orientation, gender identity or disability. The official spoke on condition of anonymity because the investigation is in the early stages.
The arrest of Jean McIntosh, 32, came the day after Philadelphia police, acting on a tip from Florida, took 10 young people into protective custody who were believed to be related to the suspects and possibly the victims.
The six juveniles and four young adults found Tuesday, ages 2 to 19, might also be related to the victims, police spokesman Lt. Raymond Evers said. Authorities are conducting DNA tests, obtaining birth certificates and trying to figure out if the 10 are part of the scheme.
The 19-year-old, identified as a niece of alleged ringleader Linda Weston, a 51-year-old convicted murderer, was found malnourished and with signs of abuse, Evers said.
McIntosh, Weston's daughter, was arrested around 3:45 a.m. after detectives had been questioning her in connection with the case, authorities said.
She faces charges of kidnapping, conspiracy and other counts and is expected to be arraigned later Wednesday, District Attorney Seth Williams said in a statement.
It could not immediately be determined whether McIntosh had an attorney. A lawyer for Weston didn't return telephone calls.
Authorities in at least two states missed opportunities to help the four adults discovered locked in the squalid basement while police say Weston stole their Social Security checks.
Weston was legally disqualified from cashing the victims' government disability checks because of her criminal past.
But she apparently did anyway, enabled in part by a lack of accountability and follow-through by government agencies and police in Philadelphia and West Palm Beach, Fla.
Weston remains jailed on $2.5 million bail, along with Gregory Thomas, 47, whom Weston described as her boyfriend, and Eddie "the Rev. Ed" Wright, 50. They face similar charges.
The case came to light Saturday when landlord Turgut Gozleveli discovered the victims after he heard dogs barking. The door to the basement room was chained shut, but Gozleveli got inside and lifted a pile of blankets to find several sets of eyes staring back at him. One man was chained to the boiler.
Police identified the victims as Derwin McLemire, 41, of North Carolina; Herbert Knowles, 40 of Virginia; and Tamara Breeden, 29, and Edwin Sanabria, 31, both of Philadelphia.
Detectives also found dozens of identification cards, power-of-attorney forms and other documents. Philadelphia police formed a task force to investigate the case as authorities try to find as many as 50 more possible fraud victims.
Knowles was reported missing in Norfolk in December 2008. According to an investigatory report by Norfolk police, Knowles' mental health case worker reported him missing when she couldn't reach him and family members failed to hear from him.
The case worker, who did not return a call from The Associated Press, reported that Knowles' Social Security checks were going to a Philadelphia address. The report said Philadelphia police went by the address and were told no one there had ever heard of Knowles.
A Philadelphia police report shows that officers knocked on the door on Dec. 5, 2008, and the woman who answered said that no one by the name of Herbert Knowles lived there, police said. The report showed no sign of a follow-up or any indication that the responding officers had any reason to disbelieve the woman who answered the door.
Norfolk police spokesman Chris Amos said authorities did not continue looking for Knowles because, as an adult, he was under no obligation to report to the case worker.
"It's not illegal to be missing," Amos said. "A lot of people are missing by choice."
Police in West Palm Beach, where Weston lived earlier this year with the four mentally disabled adults, also missed a chance to crack the case.
Chase Scott, a spokesman for the West Palm Beach police, said officers were sent to the house several times for complaints about trash and code violations.
Investigators said they're trying to piece together details of Weston's scheme, including how long it went on, how much money it brought in and how many people in all were victimized. The FBI has joined the probe.
Weston had been convicted in the starvation death of a man nearly 30 years ago, though it's unclear how much prison time she served.