(Alliance, Neb.)- An armed man who held law enforcement at bay for more than 14-hours, during a Tuesday, June 12 stand-off in downtown Alliance is believed to be responsible for the murder of 38-year old Joshua Bullock of Denver.

Investigators with the Nebraska State Patrol say during the stand-off Andres Gonzalez, 27, Alliance, told negotiators that he had killed Bullock.  Investigators believe Gonzalez killed Bullock on or around December 1, 2011 and that he disposed of his body in a remote area of Dawes County. Investigators will be searching the area for Bullock’s remains as they continue to piece together the incidents surrounding his death.

On Wednesday June 13, investigators with the Nebraska State Patrol arrested Gonzalez’s girlfriend.  Rose Siefke, 19, Hemingford was taken into custody and lodged in the Box Butte County Jail on a charge of Being an Accessory to a Felony.

“Josh Bullock’s disappearance was an active case, but we had little information to go on” said Investigative Services Lt. Monica Bartling. “Our investigation will now focus on finding Josh’s remains and bringing some closure to his family and friends.”

Bullock’s burnt out pickup was found by a rancher in a ravine southeast of Chadron on December 14. 2011. The 38-year old with ties to the Alliance and Chadron areas was last seen the afternoon of December 1, 2011 after visiting family members in Alliance.

Investigators with the Nebraska State Patrol, in conjunction with the Dawes and Box Butte County Sheriff’s Office had been investigating Bullock’s disappearance.  His information had been entered into the Nebraska Missing Persons Clearinghouse and the National Missing and Unidentified Persons System, a “Help Find Josh Bullock” Facebook page was also established by friend and family.