A Missouri man who became known as the "Package Killer" admitted to the murders of two St. Louis women more than three decades ago, bringing the total death toll from his killing spree to at least five.

Gary Muehlberg, 74, has already pleaded guilty to the killing of three women and is set to enter the same plea for a fourth in a hearing next week. He was dubbed the "Package Killer" because of his method of disposing of the bodies of his victims, whose remains were found around the St. Louis area between 1990 and 1991, according to a report from CBS News Wednesday.

Muehlberg was already serving a life sentence for the 1993 murder of Kenneth Atchison when new DNA evidence linked him to the murders of four additional victims. Atchison's body was found in a makeshift coffin in Muehlberg's basement, while other victims were found in various spots around St. Louis, disposed of in containers such as garbage cans and wooden boxes. Another victim's body was found stuffed between two mattresses.

MISSOURI MAN IN PRISON CHARGED IN 'PACKAGE KILLER' MURDERS FROM DECADES AGO: REPORT

On Tuesday Muehlberg pleaded guilty to murdering Brenda Pruitt and Donna Reitmeyer and was given two life sentences to run concurrently with two other life sentences he is currently serving.

A motive for the murders has never been disclosed.

Pruitt, 27 years old at the time of her disappearance, was reported missing by family in May 1990, with her body found in a trash can on the side of the road in October 1991. Reitmeyer, who was 40 at the time of her disappearance, was found in June 1990 inside a sidewalk trashcan.

Earlier this month, Muehlberg admitted to murdering 21-year-old Sandy Little, whose body was found inside a dresser on the side of a highway.

Muehlberg has also admitted to killing a fifth woman at his home and said he disposed of her body in a metal barrel near a car wash, but those remains were never found.