PITTSBURGH — A federal judge ruled that child welfare caseworkers in two Western Pennsylvania counties cannot be sued for alleged violation of the civil rights of a 4-year-old girl whose starved body was found stuffed into a picnic cooler.

U.S. District Judge Gary Lancaster ruled that a relative of Kristen Tatar could not prove that the government's actions directly caused the girl's death.

Tatar's 11½-pound body was found stuffed into a cooler put out for garbage collectors near her Armstrong County home in August 2003. Her parents, James Tatar and Janet Crawford, were convicted of first-degree murder and are serving life sentences.

The girl's aunt, Cathy Fondrk of Hyde Park, alleged in the 2004 lawsuit that caseworkers in Armstrong and Westmoreland counties and with the Penn State Cooperative Extension did not do enough to protect the girl. The case had been scheduled for a jury trial in February.

But Lancaster, in a ruling filed electronically on Sunday, threw out Fondrk's suit, saying she couldn't prove that the eventual harm done to Kristen was "foreseeable and fairly direct" by the caseworkers or that a state employee "acted with a degree of culpability that shocks the conscience."

"The unfortunate reality is that the danger to Kristen was her parents' incomprehensible criminal conduct," the judge wrote in the 20-page opinion. "The defendants did not create any new dangers to Kristen or cause Kristen to be any more vulnerable to her parents' inhumane treatment."

A phone number for Fondrk, who has adopted Kristen's brother and filed the suit on behalf of the dead girl's estate, could not immediately be found Monday. One of her attorneys, Jennifer Andrade, said attorneys were reviewing the decision and declined further comment.

Criminal investigators said Kristen's parents grossly underfed the girl, who was often tied to a chair with a pacifier in her mouth and rarely bathed or nurtured.

A key issue in the lawsuit was whether Westmoreland officials should have warned Armstrong County that the girl was at "high" risk for abuse when the girl moved to Armstrong.

Fondrk sued officials in Armstrong County, where the girl died; the Westmoreland Children's Bureau, which supervised Kristen's case before her parents moved to Armstrong County in 2001; and the Penn State Cooperative Extension, whose employees helped Westmoreland County supervise the girl.