Langford originally told police he had been having trouble with the bolt of his rifle sticking and was working the gun's action when his wife asked to see the weapon, then she put the barrel in her mouth and pulled the trigger.
But during a hearing in September, Simms said the woman's death was to be a suicide pact that her husband "did not honor."
Langford was also sentenced to serve two years probation, and to complete substance abuse treatment.
Rashell Langford's death apparently sparked a hostage situation at the FBI's downtown Salt Lake City office building.
On Sept. 17, 2012 six days after Langford pleaded guilty Robert Joseph Hibbard, Rashell Langford's ex-husband, allegedly took a hostage at the building after becoming increasingly agitated about his ex-wife's death and the charges filed against Shawn Langford. He allegedly initiated the episode because he wanted to speak to an FBI forensic psychiatrist, according to charges filed in 3rd District Court. Hibbard had accused the new husband of murdering his ex-wife in conversations with both The Salt Lake Tribune and Salt Lake County District Attorney Sim Gill, and indicated to The Tribune that he planned on talking with the FBI.
Hibbard told a Tribune reporter he was convinced the investigation into his wife's death was botched believing Shawn Langford should have been charged with murder.
Hibbard, 41, has been charged in 3rd District Court with one count of first-degree felony aggravated kidnapping. A scheduling hearing in the case is set for Jan. 7.