An Orange County, Fla., judge ruled Wednesday the parents of an accused killer can't be forced to testify in a civil suit against her, an attorney said.

The attorney for Zenaida Gonzalez, who is suing Casey Anthony for defamation, lost his attempt to force Anthony's parents, George and Cindy Anthony to testify in the suit, WKMG-Channel 6, Orlando, reported.

The attorney, Keith Mitnik, also tried to get information from the Anthony's private investigator, Dominic Casey, but Judge Jose Rodriguez ruled that he and Gonzalez's other attorneys cannot question the investigator.

Gonzalez, a Kissimmee mother of six, claims her reputation was damaged by Anthony when she implicated her in the disappearance of Casey Anthony's daughter, Caylee, 2, the Orlando (Fla.) Sentinel reported.

Casey Anthony, 23, faces the death penalty if she is convicted of first degree murder in the death of the child. Caylee's body was found in December less than a mile from the Anthony's east Orange County home.