A letter sent from an inmate in a Kentucky jail might shed some light on an unsolved 2011 rape case in Deputy.

According to a search warrant filed with the Jefferson County Superior Court, 63-year-old Ricky D. Dotson, also known as Ricky D. Spence, wrote a letter to the Owensboro, Ky., Police Department from the Daviess County, Ky., Jail.

In the letter, written in March, Dotson wrote he had raped women in their 80s and 90s "all over the State of Indiana," threatening to kill them if they called the cops, the affidavit said.

Dotson wrote he enjoyed having power over older women, the affidavit said, and that Kentucky authorities could not do anything about it because he committed the acts in Indiana.

Indiana State Police investigated an allegation of rape on West State Road 250 in Deputy in July 2011.

According to police, an 86-year-old woman reported a man broke into her home wearing a ski mask and holding a knife. The man struck her in the head several times, knocking her to the floor and raping her, police said.

A nightgown and towel recovered from the scene tested positive for semen and blood, according to the affidavit.

The search warrant requests a DNA sample from Dotson to test against the existing DNA evidence.

Deputies with the Daviess County Sheriff's Office arrested Dotson in May 2013. He's being held on charges of burglary, impersonating a peace officer, disorderly conduct and terroristic threatening, among several others, according to the sheriff's department. His bond was set at $25,000.

According to state police, Dotson has an extensive criminal history, including convictions for burglary, theft, arson, possession of stolen property, sodomy and rape.