Prosecutors in Platte County, Missouri, will seek the death penalty if Grayden Lane Denham is convicted in the horrific murders of his grandparents, sister, and infant nephew, CBS News reported Monday.

The bodies of Russell Denham, 82, Shirley Denham, 81, Heather Ager, 32, and her 3-month-old son, Mason, were found shot dead and burning outside their home in February 2016 in rural Kansas. After the murders, Denham, 25, allegedly stole his grandparents’ car and drove over 1,000 miles to Seligman, Arizona, where he was ultimately arrested as he walked around naked.

Denham was initially arrested on theft charges for taking the car. Last June, a grand jury indicted Denham on four counts of first degree murder. He also faces charges of animal abuse for shooting the family dog, arson for setting fire to the home, and tampering with evidence by burning the bodies and the house.

Denham has pled not guilty. His mother, Shelly Denham, told the Kansas City Star  she does not believe her son killed his relatives. ““We believe that Grayden is 100 percent innocent. We want to know who did this, but we don’t believe Grayden did it.”

What led to the murders and arson remains unclear. Denham apparently stayed at the house with his grandparents from time to time, although they no longer allowed him to use their vehicles as his license was revoked, reported the Kansas City Star.

Denham remains in jail at the Platte County Detention Center on $4 million bond and his next court appearance is scheduled for June 1. 

[Feature Photo: Platte County Detention Center]