Authorities with the Saint Charles Police Department in Missouri released age enhanced photos of the suspected I-70 Killer.

INDIANAPOLIS — New age-enhanced photos of a suspected serial killer who launched a 29-day, three-state killing spree in Indianapolis and would return to the Hoosier State to kill once more, were released this week. 

The St. Charles Police Department in Missouri released updated photos of a man known as the "I-70 Killer" in the hopes someone may recognize the suspect, who they now believe is a man in his 50s or 70s.

The I-70 Killer mostly targeted women working alone in retail stores along a 1,200-mile stretch of interstate between Indianapolis and Wichita, Kansas in April 1992.

His first victim was Robin Fuldauer, a 26-year-old working alone at an Indianapolis Payless shoe store, who was shot.

Three days later, two women working at a bridal store in Wichita, Kansas were found shot to death.

RELATED: A new look at the I-70 serial killer: Police release age-enhanced sketch

At the end of April, another Hoosier was found dead. 

The I-70 Killer's only male victim was shot to death inside his mother's ceramics store in Terre Haute. Authorities believe victim Michael McCown, who had long brown hair, was mistaken for a woman.

Years later, police are still working to find out who committed these crimes.

Police recently told Christine Byers, a reporter at KSDK, a WTHR sister station in St. Louis, that robbery was not the I-70 Killer's motive.

He only got away with about $100 from any of his crime scenes.

Most of his victims, who mostly consisted of petite brunette women, were not sexually assaulted before their death.

His sole motive, authorities believe, was murder.

RELATED: Uncovered: Indianapolis women search for answers to cold cases

"He was homicidal," St. Charles Police Capt. Ray Floyd told KSDK.

Police believe The I-70 Killer may also be responsible for some unsolved shootings and killings in Texas dating back to 1993 and 1994. 

A key piece of evidence that links the killer to the crimes committed in the Midwest and Texas was the unique gun he used, Floyd told KSDK. 

The weapon is known as an Erma Werke Model ET22 pistol — a relatively rare gun that was imported from Germany. With a foot-long barrel, only 6,500 models were ever made. 

The suspect is described as a thin man with dull red hair, or sandy blonde hair with a red tint. He is between 5 feet, 7 inches and 5 feet, 9 inches tall and between the ages of 52 and 70 years old with lazy eyes.

Here's a full summary of the crimes: 

• April 8, 1992: Robin Fuldauer was found shot to death inside a Payless shoe store in Indianapolis.
• April 11, 1992: Two women, Patricia Smith and Patricia Magers, were found shot to death inside a bridal store in Wichita, Kansas. This crime gave detectives one of their biggest leads as a man who came to the store to pick up a cummerbund saw the killer inside the store. The killer tried to order the man to stay inside the store at gunpoint with the distinct murder weapon, but the man ran away and gave police the description that has been used in police sketches.
• April 27, 1992: Michael McCown was found shot to death at Sylvia's Ceramics in Terre Haute, Indiana.
• May 3, 1992: Nancy Kitzmiller was found shot to death in St. Charles.
• May 7, 1992: Sarah Blessing was found shot to the death at a small store in Raytown, Missouri, near Kansas City.
• Sept. 25, 1993: Mary Ann Glasscock was killed at the Emporium Antiques stores in Fort Worth. 
• Nov. 1, 1993: Amy Vess was shot to death in a dance apparel store in Arlington, Texas. 
• Jan. 15, 1994: Vicki Webb was shot in the back of the head in the Alternatives gift shop but survived. Floyd said she told police the sketch of the I-70 killer matched the face of her attacker, but Texas authorities have not been convinced of the connection as different guns were used in each spree

The St. Charles Police Department is offering a $25,000 reward for any information leading to an arrest in this case.

Anyone with information should call Missouri authorities at 1-800-800-3510. Those with leads can also call Crime Stoppers of Central Indiana at 317-262-TIPS (8477) or 800-222-TIPS (TIPS) and submit a voice tip. 

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