Keighley Ann Alyea Update: Last trial begins in murder of Kansas teen

(CBS) - The trial of the last of the three men charged with the kidnapping murder of 18-year-old Kansan Keighley Alyea began Monday in Johnson County District Court.

PICTURES: Keighley Ann Alyea Murdered

Joseph Mattox, 22 has pleaded not guilty to the first-degree murder and aggravated kidnapping and aggravated robbery of Alyea, reports the Kansas City Star.

According to police, three men, including her ex-boyfriend, Justin Hilt, and his cousin, Mattox, kidnapped Alyea southwest of Kansas City on Sept. 30, 2009, reports the Star.

Alyea suffered 30 stab wounds a fractured skull. Her body was found days later in a field.

Hilt was sentenced to almost 69 years in prison in July 2010. The other man, Gerald "Scott" Calbeck, pleaded guilty to a reduced sentence of second-degree murder, aggravated kidnapping and aggravated robbery, and will be sentenced on May 4, according to the Star.

MORE ON CRIMESIDERJuly 14, 2010 - Keighley Ann Alyea's Ex-Boyfriend Sentenced in 18-Year-Old's MurderOctober 7, 2009 - Missing Woman Keighley Ann Alyea Found Dead, Three Arrested