Missing 9-year-old Indiana girl was found dead.

CNN - A missing 9-year-old Indiana girl has been found dead, and the family friend who was watching her before she disappeared was charged with murder Monday night, authorities said.

Allen County sheriff's spokesman Cpl. Jeremy Tinkel said investigators found the body of Aliahna Lemmon in the county, but he wouldn't say where. He also said 39-year-old Mike Plumadore was "interviewed by police and taken into custody at 9 p.m. and charged with murder."

Plumadore, who had been watching Aliahna and her sisters before she was reported missing late Friday, is scheduled to appear in court Tuesday.

FBI agents earlier Monday descended on the rundown mobile home park in Fort Wayne where Aliahna lived and was last seen. It's a known haven for registered sex offenders, though Plumadore is not on Indiana's registered sex offenders list. He has a criminal record in Florida and North Carolina that includes convictions for trespassing and assault.

According to a state website, 15 registered sex offenders live at the mobile home park that numbers about two dozen homes.

More than 100 emergency workers searched for Aliahna around the mobile home park Saturday, though no active search was done Sunday. Tinkel said the same size search could not be sustained because of the Christmas holiday.

"Children don't just walk away during Christmastime," Aliahna's step-grandfather, David Story, said Monday afternoon.

Aliahna's mother, Tarah Souders, told The Journal Gazette earlier Monday that her daughter had vision and hearing problems and suffered from attention deficit disorder and emotional problems. Aliahna and her sisters were staying with Plumadore because their mother had been sick with the flu and Aliahna's stepfather works at night and sleeps during the day.

Plumadore told the newspaper Sunday that he left the three girls in his mobile home about 6 a.m. Friday and went to a gas station about a mile away to buy a cigar. Authorities have said the store's surveillance video shows him there about that time.

"I had dead-bolted the door," he said. "When I got back, all the girls were here."

He said he smoked his cigar and went back to sleep, then woke up about 10 a.m. when Aliahna's mother called. After that call, he realized the door to the home was unlocked and that Aliahna was gone. He said Aliahna's 6-year-old sisters told him Aliahna had left with her mother.

Plumadore said it wasn't until he talked with Aliahna's mother about 8:30 p.m. that they realized she was missing and police were notified.

Tarah Souders said the miscommunication caused the delay in determining that Aliahna had vanished.

"She's never wandered off," Souders said. "She's never done anything like this before."