A month before she was shot dead outside her home, Heather Marin's husband allegedly held a gun to her head and threatened to kill them both in front of his 'least favorite' daughter, according to her family.
Heather, 50, was allegedly murdered by her husband Robert Marin, 60, outside their gated community home in Waddell, Arizona, on March 16, amid a bitter divorce between the couple.
Prosecutors said Robert then lit up a cigar while covered in his wife's blood and watched as their 17-year-old daughter desperately attempted CPR.
Heather's brother Aaron Cooley told the Daily Mail that there were urgent red flags before the tragedy, including an alleged domestic violence incident a month prior when Heather went to pick up items from the home, about 30 miles west of Phoenix.
Cooley said Heather moved in with him in January and had filed for divorce, but that her estranged husband flew into a frenzy when she tried to retrieve more of her possessions from the home in February. '[Robert] held a gun to her head and threatened to kill her then himself,' Cooley said.
Cooley added that his sister warned her family about her husband's threats, but did not report him to the police because their youngest daughter was still living at the home, and she was terrified of Robert's 'temper'.
'There was a lot of fear involved,' he said, adding that Robert allegedly made similar threats in the past to the rest of her family.
Cooley said the couple had two daughters, but recalled Robert 'made it clear that he always preferred their oldest daughter... that's the kind of man he is.'
Heather Marin, 50, was shot dead outside her home in Waddell, Arizona on March 16, prosecutors say by her husband Robert Marin, 60, in the midst of a divorce
Heather's brother Aaron Cooley told the Daily Mail that there were urgent red flags before the tragedy, including an alleged domestic violence incident a month before where Heather's husband allegedly 'held a gun to her head' and threatened to kill them both
Robert Marin, 60, is facing first-degree murder charges after allegedly shooting his wife before lighting a cigar and watching as her daughter desperately tried CPR. He has not yet pleaded
According to a probable cause affidavit first shared by Law & Crime, Heather Marin was shot dead following an argument with her husband about their teenage daughter staying with him in their Waddell home.
The 17-year-old told police that she and her father had a 'verbal argument' earlier in the evening, during which he 'expressed hatred' toward Heather, the reported affidavit said.
The domestic situation escalated as the daughter 'retreated' to her bedroom, and she 'overheard (Robert) Marin make a heated and angry phone call' to Heather to tell her he 'could not deal with their daughter and did not want her to stay in the home.'
The teenager said her mother then tried to call her twice but she did not answer because she was afraid 'it would upset her father' - before she then heard 'screaming' from their garage area around 20 minutes later.
'As she walked towards the garage entrance door from the house, she distinctly heard her mother pleading, 'Please don't kill me, please don't kill me,' the reported affidavit alleged.
The teen then heard four gunshots, prosecutors said.
The daughter then yelled at him, 'Why would you do this?', as he lit up a cigar and sat covered in Heather's blood while he watched his daughter attempt CPR, prosecutors alleged in the affidavit.
Heather Marin was not living in the home at the time, but went to the property after receiving a call from her daughter and heard 'yelling' in the background, her brother said
Police said Heather was shot dead outside her gated community home in Waddell, Arizona
Robert Marin, seen in court, was accused of sending threatening messages to his wife, and the couple were getting a divorce at the time she was shot dead, prosecutors say
Cooley said he understood that his sister's marriage was troubled, but he told the Daily Mail that he 'never thought (Robert) would go this far.'
The heartbroken brother said he fears that Robert used the argument with his daughter as a ploy to lure Heather to their home, and said it 'wouldn't surprise me' if it was a trap.
'He was ready and waiting with a gun,' he said. 'I have to believe it was premeditated.'
Robert Marin was arrested at the scene, and is now facing charges of first-degree murder, domestic violence, disorderly conduct with a weapon, and tampering with evidence, records show.
He has been locked up on a $2 million cash bail since the shooting, but this week Marin's attorneys argued to downgrade it to a $200,000 surety bond - a prospect that Cooley said had his family living in fear.
Heather Marin, seen in her youth, had avoided reporting her husband's alleged domestic abuse to the police over fears about his 'temper' toward their daughter if she did so, her brother said
Speaking to the Daily Mail on his way to the courthouse to protest the request, Cooley said Robert could 'easily' pay a $200,000 bond, and said he hopes 'common sense will prevail' in keeping the alleged killer behind bars.
'It is absurd – it shouldn’t even be a possibility,' he said of Marin's bond request, describing him as a 'cold blooded killer.'
‘We are 100% afraid that he could bail out, some family are too afraid to even go to court today because they’re so freaked out,' he said.
‘He has made direct threats to our family, he said he would blow the world up.’
On Thursday, a judge rejected the request to lower Marin's bail.
Robert Marin has not yet entered a plea in court. The Daily Mail has attempted to locate his attorneys for comment.