TLDR
Prosecutors in Maricopa County, Arizona, have charged 60-year-old Robert Marin with first-degree murder after a police affidavit alleged he shot his estranged wife, Heather Marin, in the family garage while their teenage daughter was inside the home.
What happened inside a Phoenix garage is now laid out in a detailed probable cause affidavit, which describes a fatal shooting, a teenage witness, and a claim of premeditation. The document, obtained by Law & Crime, forms the backbone of the case prosecutors are building.
Marin, described in the filing as an avid gun owner, is accused of killing his estranged wife during a conflict over their daughter’s living arrangements. He was arrested at the scene and is being held in the Maricopa County Jail on a $2 million cash bond, according to the affidavit.
Alleged Killing Inside Phoenix Garage
According to the affidavit, tension in the home escalated after an argument between Marin and his teenage daughter over her staying with him. The daughter later reported that Marin made an angry phone call to Heather Marin, telling her he could not deal with their daughter and did not want her to remain in the home.
The daughter retreated to her bedroom, the document states, and spoke with her boyfriend by phone. She received two calls from her mother, around 8:39 p.m. and 9:09 p.m., but did not answer because she feared it would further upset her father. Sometime afterward, she heard screaming from the garage area.
Affidavit Details Daughter’s Account
The affidavit alleges that as the daughter approached the interior door to the garage, she heard her mother pleading, saying, according to the document, “Please don’t kill me, please don’t kill me,” followed by about four gunshots. When she opened the door, she reportedly saw her mother bleeding on the ground and Marin standing near or over her holding a firearm.
The filing states that the daughter shouted at her father, asking why he had done this. Marin allegedly shrugged, left the garage, then returned and smoked a cigar near his wife’s body while his daughter performed CPR and called 911. Responding deputies from the Maricopa County Sheriff’s Office reported finding Marin in the garage with blood on his clothing and shoes, along with a firearm, holster, and spent casings.
Prior Threats and Premeditation Claim
Investigators also documented the daughter’s account of an earlier, unreported domestic violence incident in February 2026. In that episode, according to the affidavit, Marin allegedly held a firearm and threatened to shoot Heather Marin in the head before killing himself. The daughter further described seeing screenshots of text exchanges between her parents containing hateful and threatening language.
The affidavit notes that Marin kept multiple unsecured firearms in the home, including pistols and hunting rifles, as well as a large safe storing additional firearms and ammunition. Detectives argue in the document that the alleged prior threats, Heather Marin’s reported pleas for her life, and Marin’s “indifference after the shooting, electing to smoke a cigar rather than render aid,” support a finding of premeditation. Deputies also reported a strong odor of alcohol from Marin during his transport for questioning.
The case remains in its early stages, and the allegations in the affidavit have not yet been tested in court. Marin, who is presumed innocent unless and until proven guilty, is expected to face further court hearings as prosecutors pursue a first-degree murder charge.
