A married couple arrested Thursday at a Days Inn Hotel in Missouri after a week-long violent crime spree that ran the gamut from armed robbery to murder, is now under investigation for a triple homicide.

Brady Kane Witcher, 41, and Brittany McMillan, 28, were arrested in Hazelwood, Missouri on arrest warrants out of Alabama for the kidnap and murder of Kellie Ann Hughes, 31, whose body was found Dec. 13 in the woods near Birmingham, according to the St. Louis Post-Dispatch.

Police found Hughes after a woman called 911 to say that she had been kidnapped and was being held against her will in an apartment complex in Birmingham. Police were able to track her cellphone to the apartment where the woman was found at the bottom of a stairway she had fallen down, bound with zip ties. The woman told officers she had been kidnapped because she knew about Hughes’ murder. She later led them to the body.

After Hughes’ corpse was found in the woods, Witcher was caught on a surveillance camera at a Clarksville, Tennessee, Walmart where Witcher pulled a gun on an employee and escaped in a dark Nissan Maxima which was driven by McMillan. Later that day both suspects were caught on surveillance cameras at a different Walmart and left that store in a Ford Fusion. Police tried to pull the couple over for a traffic violation but the couple fled.

Later that evening, Clarkesville police answered a 911 a call about a man chasing a woman into the woods and a shot being fired. Officers who answered the call found the Ford Fusion but no sign of Witcher or McMillan.

The pair then apparently broke into an apartment and held a married couple in a closet at gunpoint overnight. The St. Louis Dispatch reports that the husband was stabbed but managed to escape with his wife after Witcher and McMillan stole their 2012 GMC pickup.

Investigators now believe the Witcher and McMillan are tied to a triple homicide after police found three bodies at the registered address of a different vehicle the duo had in their possession when they were arrested.

Those victims, who lived in Bethalto, Missouri, have been identified as Shari Yates, 59, her son Andrew Brooks, 30, and John McMillian, 32. “It is too early to say if there is a direct connection to our victims,” according to Brian Koberna, deputy commander of the Major Case Squad of Greater St. Louis. “We’re still trying to determine how they knew the suspects.”

McMillan was a former resident of Bethalto, where the three victims were discovered.