By Hector Gutierrez
Rocky Mountain News
March 20, 2008

A 21-year-old man serving time for vehicular eluding resulting in death and attempted second-degree murder was sentenced Wednesday to spend 40 more years in prison in the 2005 shotgun slaying of another man.

Matthew Wartena was convicted in January of second-degree murder in the August 2005 shooting death of Aaron Rivera, 25, outside a townhome complex in the 8100 block of Welby Road.

Adams County district Judge Harlan R. Bockman also gave Matthew Wartena five years of parole for second-degree murder and motor vehicle theft.

The 40-year sentence will run consecutive to the 66 years handed down by a Jefferson County judge for vehicular eluding and attempted second-degree murder.

Wartena’s accomplice, Westley J. Ybarra, also 21, pleaded guilty to second-degree murder and was ordered to serve 36 years in prison in Rivera’s killing.

Ybarra also is serving a six-year prison term for introducing contraband to the Adams County Jail.

The two assailants had been angry with the victim because they believed he stole some property from them, according to testimony.

The pair then conspired with a woman to lure the victim to the townhomes where the shooting occurred, according to testimony.

Ybarra admitted to stabbing the victim during the confrontation before Wartena fired the shotgun blast.

The woman who helped lure the victim testified in Wartena’s trial and was not charged. Two days after Wartena killed Rivera, he was involved in a high-speed chase and the hit-and-run death of a California man.

He fired shotgun rounds at a driver who was trying to follow Wartena and a teenager after he saw the two trying to steal a car in Arvada.

When law-enforcement officers chased Wartena, his Honda struck a vehicle carrying 19-year-old Brian Kapko on Interstate 76. The vehicle rolled and Kapko was killed.