() A former lead detective who investigated Ted Bundy said the serial killer gave police “crucial information” that eventually led to the arrest of “Green River Killer” Gary Ridgway.

Roger Dunn, an ex-King County, Washington, detective, joined “Banfield” on Tuesday to discuss his experience with Bundy and Hulu’s documentary “Dialogue With The Devil,” which delves into Bundy helping the police in their investigation and eventual capture of Ridgway in 2001.

Ridgway was convicted of killing 49 women and girls in the Seattle and Tacoma, Washington, areas in the 1980s and 1990s. He was termed the Green River Killer because several of his victims were found in the Seattle-area stream.

Ridgway pleaded guilty to 48 of the crimes in 2003 and was sentenced to 48 life sentences without the possibility of parole to be served consecutively.

He confessed to the 49th murder in 2011, and an additional life sentence was added. He is incarcerated at the Washington State Penitentiary in Walla Walla, Washington.

Dunn said police had to take Bundy’s information “with a grain of salt” given his impending execution, which took place Jan. 24, 1989.

Despite this, he says, “When it came right down to it, (he) gave crucial information about the crime scene … where the victims were dumped.

“No one else had that knowledge other than the killer. I don’t know what Bundy’s motive [was]…”

‘s Steph Whiteside contributed to this report.