A suburban Chicago man admitted he locked his two little girls in a wire cage hidden in the back of his pickup truck, police said.

Ricardo Gonzalez of Midlothian was arrested Monday after a woman at a gas station in Posen heard a crying child and spotted him pushing small hands back into a cage, police said.

"She didn't think this was right and notified police right away," Posen Deputy Police Chief Vickie Paggi told the Chicago Tribune.

Gonzalez was taken into custody before leaving the gas station.

Gonzalez admitted to locking his girls, ages 2 and 5, in a cage to control them so they wouldn't run away, police said. He had erected a wire cage behind the driver and passenger seats of his Chevrolet S10 truck, police said. Black-tinted windows and a large plywood board in the truck's window back window concealed the cage.

Gonzalez told police he used the cage because he didn't have a baby sitter. Police said the girls did not live in the cage around-the-clock.

The 35-year-old faces charges of misdemeanor child endangerment. Cook County prosecutors were exploring Thursday whether the charge could be upgraded to a felony.

A telephone listing for Gonzalez couldn't be found.

The children were turned over to the Illinois Department of Children and Family Services and placed in foster care Monday. Police said there was no evidence the girls were in poor health.

DCFS spokesman Kendall Marlowe said the agency was investigating allegations of abuse against the father. It previously has investigated the allegations of neglect against the girls' mother, Yesenia, which were found to be substantiated. In 2006 and 2007, it provided "supportive services" for the family, but Marlowe could not say what type of services those were.

Marlowe also could not say where the children were placed but said: "We always look first to family when making a placement. When family is for some reason not an option, we then look to place the child in their community so that children can maintain ties to their extended family."

Gonzalez will appear in court July 31. It isn't clear if he's retained an attorney.

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