Updated

A potential witness in the killing of an 8-year-old California girl has recanted her statements about seeing a possible suspect running from the girl's home and "is no longer credible," a sheriff's department spokesman said Thursday.

Sgt. Chris Hewitt said that while meeting with a sketch artist and detectives Wednesday, the unidentified witness refused to provide a description so a composite sketch could be made of the man.

Her account had been considered significant to identifying Leila Fowler's killer because her earlier descriptions had matched the one provided by Leila's 12-year-old brother, who was home alone with his sister when she was stabbed to death. The witness, however, reported seeing the suspect headed in the opposite direction than the brother had reported.

"Though this may seem like a setback in the investigation, it is actually a positive result in that it allows the investigators to narrow the scope of their investigation," Hewitt said of the witness' statements turning out to be unreliable.

FBI agents are now assisting with the investigation into Leila's death. They said they hope the brother's description of the assailant will provide more leads.

Investigators so far have found no link between the attempted kidnapping of a 15-month-old girl in Placerville on Tuesday and Leila's slaying Saturday in her home in Valley Springs, about 50 miles away.

Although authorities still plan to do a DNA test on the 44-year-old kidnapping suspect, "detectives have determined it unlikely that there is a connection between the two crimes," Hewitt said.