ST. LOUIS COUNTY (KTVI) – Local authorities hesitate to say it, but it appears Theodis Hill of Jennings is a serial killer. The 49-year-old admitted to the strangling deaths of three St. Louis women and two additional murders in Arkansas.

It began in November 2006 when 56-year-old Fanny Mae Hill was found murdered in her Central West End apartment. In 2009, a match finally came to DNA found on the towel used to kill her. In 2010, Hill pleaded guilty to second-degree murder and received a 15-year prison sentence for the crime.

While in prison, Hill wrote to a St. Louis police detective, indicating he had information on other homicides, providing details only the killer would know.

According to court documents, Hill went into chilling detail about how he did drugs with 46-year-old Janice Mayhew in the Baden neighborhood in September 2008, and then killed Mayhew to keep her quiet about an unrelated robbery.

In the letters, Hill told the detective he’d been drinking doing drugs with 22-year-old Sierra Sullivan in a north St. Louis home in July 2009, and confessed to killing her for taking drugs off the nightstand.

Hill had already pleaded guilty to the 2009 strangulation murder of 40-year-old Marissa Lowe in Arkansas. He wrote to a prosecutor there confessing to the murder of 48-year-old Katherine Dawson. He’ll face life without parole when and if he’s formally convicted of these added crimes.

St. Louis authorities said Hill was a suspect in one of the cases but there wasn’t enough evidence for charges. The DNA sample matching Hill to Fanny Mae Hill’s murder in 2006 came from an unrelated arrest later, and by that time, Theodis Hill had already killed the other four women.