The conviction of a Post Falls man who was sentenced to 100 years in prison for raping and strangling his former girlfriend has been upheld by the Idaho Supreme Court.

Billy L. Joslin Jr., who was convicted two years ago by a Coeur d’Alene jury, appealed. He argued testimony from an ex-wife slandered his character and was illegal.

A court rule prohibits using a character witness to show that a defendant is likely to commit a crime.

But justices stood by the conviction, countering that any influence the testimony had on jurors was insignificant.

Joslin was convicted in 2017 of raping his ex-girlfriend after a jury heard testimony from an additional 18 witnesses who outlined the events of Aug. 25, 2016, in which Joslin waited for his ex-girlfriend to come home for lunch, followed her inside her Hayden home and then choked and raped her before driving her back to her job in her own car. He kept the victim’s car and apartment keys and promised to pick her up after work.

After the crime was reported, Joslin eluded authorities. He was later arrested hiding in a friend’s shop in Post Falls.

As the case unfolded, investigators learned Joslin had raped a woman in a similar fashion a decade earlier, served time in prison, and committed a mirror image of the crime within eight months of his release from prison.

First District Judge Cynthia K.C. Meyer called Joslin, then 39, a violent and professional criminal who showed no remorse.

“You are volatile, mercurial, you lack insight, you have an attitude of entitlement, you lack remorse,” Meyer said. “Society needs to be protected from you for a very long time.”

Justices said despite testimony from an ex-wife who portrayed Joslin as a violent man capable of committing another crime, the 18 witnesses, including health-care workers, friends and coworkers of the victim, as well as the victim, in addition to photographic evidence of the victim’s injuries, was enough to sway a jury. The jury found Joslin guilty of rape, attempted strangulation and deserving of a persistent violator enhancement.

“To the extent the district court erred in admitting the testimony of Joslin’s ex-wife, any such error was harmless,” the justices wrote in their decision.