Wrongful death lawsuit says SLC police didn’t do enough to stop murder of Lt. Gov.’s cousin

Shauna Mayne, the mother of a woman shot to death by her ex-husband in 2022, is now suing the Salt Lake City Police Department, claiming officers failed to intervene in the days leading up to the murder. 

In August 2022, Amanda Mayne was killed by her ex-husband, Taylor Martin, who then turned the gun on himself. 

It was a high-profile case of domestic violence. Mayne was Utah Lt. Gov. Deidre Henderson’s cousin, and in the months following Henderson said the murder highlighted the gaps in the system, particularly how law enforcement interacts with victims of intimate partner violence. 

Those same gaps are detailed at length in the wrongful death suit, filed in Utah’s 3rd District Court in late March, which alleges the Salt Lake City Police Department “did not properly investigate the situation and assess its lethality or take appropriate steps to protect Amanda. If it had, she would still be alive today.” 

In the 1996 case Tiede v. State, the Utah Supreme Court ruled that the government has immunity in wrongful death cases. But Mayne’s lawyers say that case should be overturned, arguing “it relied on an incorrect assessment of the history of Utah’s wrongful death actions.” 

“The Utah Constitution enshrined the common understanding that no one — including a governmental entity — enjoys immunity for negligently causing the death of another, under Utah law,” the complaint states. 

‘His propensity to violence was known’ 

Martin had a lengthy rap sheet detailed in court documents, which includes charges of domestic violence, tampering with witnesses, assault, criminal mischief, damaging property, violating probation, making a bomb threat and threatening a judge. 

Shortly after he and Mayne married, he spent about a year in jail. Upon his release in 2019, Mayne fled to her parents house, but Martin continued to harass and threaten the family. 

During a 2019 investigation, police told Shauna Mayne how Martin was “making plans to kill Shauna and her son.” Officers learned this from speaking to one of Martin’s co-workers. 

“The police officer shared her belief that the co-worker was just trying to get Martin in trouble, but Shauna urged the officer to take the threat seriously,” court documents read. 

In Jan. 2022, Taylorsville Police investigated more threatening texts Martin sent to Shauna Maybe, including one that read “your daughter will be killed.” Those texts and the investigation were documented in a police report. 

Then on Aug. 15, 2022, two days before the murder, Salt Lake City police responded to Mayne’s workplace after Martin showed up and made threats to her and her boyfriend. 

Martin claimed it was a coincidence, telling officers he had gone to Mayne’s workplace looking for employment. As officers escorted him off the property, Martin told police “I’m not going back to jail. …you guys are going to kill me before you get me into those gates.” 

The next day, Martin sent a threatening email to the same workplace, which Salt Lake officers also investigated. 

On Aug. 17, 2022, between 4 a.m. and 5 a.m., Martin shot Mayne 14 times as she arrived at a bus stop in Taylorsville, headed to work. He then walked down the street and fatally shot himself. 

The lawsuit alleges that the behavior Martin exhibited to Salt Lake City Police in the days leading up to the murder warranted more action from officers. It also argues that Salt Lake City Police missed multiple red flags suggesting Martin posed a danger to Mayne and her family. That includes the January 2022 Taylorsville Police report. 

“His propensity to violence was known,” the complaint reads, and Salt Lake officers “had access to the numerous police reports filed against Martin in other jurisdictions, including the police report filed with Taylorsville,” the complaint reads. 

The lawsuit also claims Salt Lake police failed to properly investigate witness statements, communication from Martin, and to “arrange, facilitate and provide” Mayne with services available to victims of violence.

Lawyers are requesting a jury trial, according to court documents, and are seeking damages for the cost of medical treatment, lost earnings, “pain, suffering, mental anguish and loss of life” and more. 

After Mayne’s murder, Henderson successfully lobbied the Utah Legislature to increase funding for domestic violence resources and pass a law mandating all police officers conduct an assessment when responding to cases of intimate partner violence that determines how at risk the victim is. 

Mayne’s family said that assessment, called the lethality assessment protocol, would have underscored how dangerous Martin was while preventing the lapse in communication between different police departments.

Salt Lake City Police declined to comment on active litigation.