A former Colorado jail officer has been arrested and charged with murdering his wife, three years after local detectives allegedly covered up evidence of his crime and ruled her death a suicide - even though she was shot in the back of the head.

Ashley Fallis' family never believed the 28-year-old mother of three had killed herself and they campaigned for three years for police in Evans, Colorado, to reopen the case and investigate whether her husband, Tom Fallis, was responsible for the New Years Day 2012 shooting.

Tom Fallis, 34, was arrested today in Bloomington, Indiana, where he had been living with the couple's three young children after fleeing Colorado.

He will be extradited back to Colorado to stand trial.

Scroll down for video

Murdered: Ashley Fallis, 28, was shot in the back of the head after a New Year's party in 2012. Her death was ruled a suicide after minimal investigation by local police

In cuffs: Three years after his was was killed, Tom Fallis was arrested in Bloomington, Indiana, for Ashley's murder. He will be extradited back to Colorado to stand trial

Didn't give up: Ashley's parents Joel Raguindin (left) and Jenna Fox (right) campaigned to have their daughter's case re-opened after claiming the police covered up evidence of a crime

Ashley's parents, Jenna Fox and Joel Raguindin, are flying to Indiana to take custody of their grandchildren and raise them as their own.

A grand jury indicted Tom Fallis for murder after police agreed to reopen the investigation following a series of damning reports by KDVR-TV reporter Justin Joseph.

Ashley was found shot in the back of the head after a booze-fueled New Year's Eve party at the Fallis home turned sour when Tom Fallis learned someone had brought marijuana to the party and became enraged.

Fallis, who was working as a Weld County corrections officer, called 911 in screaming hysterics to say his wife had committed suicide. He angrily denied that he had anything to do with his wife's death and Evans police quickly ruled that Ashley had died of a self-inflicted gunshot wound.

Mr Joseph uncovered shocking evidence that was either ignored or left out of a police report by Evans police officer Michael Yates. Yates was later cleared of criminal charges by an independent investigation, but still faces an internal review, according to the Denver Fox affiliate.

Tom Fallis became irate in a police interview when an interrogator suggested his wife could not have shot herself in the back of the head

Ashley Fallis could be heard screaming for her husband to get off of her before the gunshot that took her life

The bedroom where Ashley was found was a mess and showed signs of a struggle - despite Tom Fallis' claims that he and his wife had never had a fight

Among the details that KDVR uncovered: A friend at the party who said he overheard Ashley crying for her husband to get off of her; a neighbor who said he heard outside his window as Tom Fallis confess to killing his wife; scratches and defensive wounds on Tom Fallis' chest that indicated there had been a struggle; reports from Ashley's parents that he had been violently angry before Ashley's death; clear evidence of a struggle in the bedroom where Ashley's body was found - including

Most shockingly, one of the the Fallis' young children, age six, told police that she saw 'daddy getting the gun ready' and 'saw daddy shoot mommy.'

'He was irate and explosive. He was abusive with his words and he was telling us he hated us, and to ‘F everybody’ and then he went into the room and slammed the door,' Ashley's mother, Ms Fox, told KDVR.

Ms Fox and Mr Raguindin never gave up their search for justice. They rallied friends and supporters to picket outside the police station when Ashley's death was ruled a suicide. They have targeted Officer Yates and called for him to be criminally indicted.

They raised money for lawyers fees to win visitation rights for their grandchildren and set up a memorial for their Ashley.