Suzanne Wingo is an investigator with the Bureau of Alcohol, Tobacco, Firearms and Explosives, and an associate of Rachel Walling. She is "midthirties, athletically built, with a short non-nonsense cut to her auburn hair."
In 2012, she was contacted by Walling to relay a request from LAPD detective Harry Bosch regarding an expedited database search for a firearm (serial number BER0060_52) related to one of Bosch's investigation. The gun in question was a Beretta Model 92 that had been used in the murders of Anneke Jesperson, Walter Regis, Eddie Vaughn, and possibly others. She later met Bosch outside of the Police Administration Building to inform him that the gun that Bosch had recovered had originally been sold to the government of Iraq in early 1989 for use by the Republican Guard. All such weapons were supposed to have been destroyed by the U.S. Army at the end of Operation Desert Storm, but this particular weapon somehow ended up in Los Angeles a year later.