On July 31, 1990, Catharine Ann Ryder Newstrom, 47, was found shot to death along with her employer, 60-year-old Charles William Sparboe, inside the Treasure State Silver & Gold coin shop in Billings, Montana. Both victims had been shot in the head with a .22 caliber handgun, and about $54,000 in coins and gold were taken in the robbery.

In the days before the killings a man posing as a farmer and claiming to have funds from a farm sale had been visiting the shop. Jim Sparboe later told investigators the visitor’s smooth hands and the fact he parked some distance away made him uneasy. That description and a composite helped link the suspect, identified as Charles Thurman Sinclair, to the scene. Sinclair was connected to a series of similar coin shop slayings across the western United States and was called the Coin Shop Killer.

Sinclair was arrested in Kenny Lake, Alaska, on August 16, 1990, but died of heart failure in an Anchorage jail on October 30, 1990, before Montana authorities could proceed to extradition and trial. Does anyone have further information about Newstrom, the shop, or those days in Billings that could shed light on the case?