A registered sex offender was arrested Sunday after a 10 year-old girl was found dead in Rockford, Illinois.

Rockford Police Chief Carla Redd said that 44-year-old Antonio Moore allegedly took two sisters –ages 10 and 6 — from their front yard, where they were outside playing, according to the Rockford Register Star. The younger girl got away and told her mother that her sister had been abducted. Redd said the mom alerted police just after noon.

Police were called again about a half hour later when a man found an unresponsive child outside a home on 10th Avenue. Officers arrived and began CPR before medical personnel arrived and took her to a hospital, where she was pronounced dead.

Redd said that a police dog located Monroe a few blocks away, and he was arrested after a short struggle. He was taken to the hospital for an unrelated issue and will be booked into jail when he is released from the hospital.

Both girls were strangled, the chief said. The younger girl was treated for her injuries and released.

Monroe has been charged with first degree murder, attempted murder, two counts of kidnapping, and one count of aggravated battery via strangulation.

“We’re not sure why he was in Rockford,” Redd said during the news conference Sunday night, noting that Rockford police had no contact with Monroe, who lived 100 miles away in Blue Island.

Court records show that he was convicted of criminal sexual assault charges in Peoria County, about 135 miles away, 13 years earlier and is on the state registry of sex offenders.

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[Featured image: Antonio Moore/Illinois State Police]