Mother of Slain Baby Urges Parents to Be Cautious : Crime: The woman says she ignored warnings about leaving the 13-month-old with her boyfriend.

A Lancaster woman whose 13-month-old daughter was raped and killed, allegedly by her own boyfriend, tearfully urged parents Wednesday to not leave their children alone with others “no matter how much you trust them.”

Renate M. Schmidt, 20, said she could not believe at first that her boyfriend of four months--Robert B. Patalsky, 23, of Lancaster--had killed her daughter, Brianna Lee. But she said she now has no doubts that Patalsky--who pleaded not guilty Tuesday to a murder charge--was responsible for the death. He should be sentenced to life in prison without parole if convicted, she said.

Schmidt told reporters that before the death she had not worried about leaving the child with Patalsky--even though his mother had cautioned Schmidt that her son might harm the infant and the baby had suffered a burned hand while under his care about a week before her death.

The infant’s death Saturday was a terrible lesson that other parents should heed, she said. “No matter how much you love and trust a person . . . don’t leave your children alone with anyone,” Schmidt said.

Prosecutors allege that Patalsky raped, sodomized and killed the baby by violently shaking her Saturday afternoon after Schmidt and Patalsky’s mother left the Lancaster house they shared to go shopping.

Prosecutors said they are convinced that Patalsky assaulted and killed the infant because he admits being the only adult present. Schmidt said that also convinced her, along with seeing photographs of her baby’s bruised and bloodied body.

Schmidt said Patalsky had hit her recently but had not appeared to mistreat her daughter or his own two young sons, who now are in county custody, despite the warnings she got from his mother. Schmidt said the mother gave her one such warning as they shopped together the day Schmidt’s daughter died, telling her that the children should not be left alone with her son because he might harm them.

Although Schmidt said she had seen no evidence that Patalsky’s sons were mistreated, prosecutors said the boys had been taken from his custody and given to his parents because of unspecified prior problems.

According to court records, Patalsky’s mother had told sheriff’s deputies he had been a drug user.

He was being sought at the time of the infant’s death for traffic warrants and on criminal charges in Orange County, where authorities issued an arrest warrant for him in February after he missed a court hearing on misdemeanor assault and child endangerment charges stemming from a 1989 incident in Garden Grove. Schmidt said she knew only of the traffic warrants.