In the quiet community of Gig Harbor, Washington, Diane Michele Perron, a 76-year-old woman, was a beloved figure, often described as the "neighborhood grandma". Her life, however, came to a tragic and violent end on October 3, 2020. On that Saturday evening, police were called to her home in the 6500 block of Valley View Drive Northwest for a welfare check. Upon arrival, they discovered a scene of violence; her front door had been forcibly kicked in, and inside, they found her body.
The Pierce County Medical Examiner's Office later confirmed that Diane had died from multiple gunshot wounds, ruling her death a homicide.
The investigation quickly focused on her neighbor, Mark Allen Erisman. Neighbors reported that Erisman, who had a history of mental health issues, had become increasingly agitated with Perron. He harbored the belief that she was using electronic devices to frighten away the birds and other wildlife from his yard, creatures he considered to be like family. This unfounded belief appears to have been the catalyst for his deadly actions. In the days leading up to the incident, Erisman had been heard yelling and making threats, prompting concerned neighbors to contact authorities. Despite a visit from sheriff's deputies and a mental health co-responder, his agitation continued to escalate.
The events of that fatal day unfolded with chilling clarity. Erisman was seen on Perron's own security cameras approaching her home with a handgun. After shooting out her surveillance camera, he kicked in her door and shot her at least seven times. Later that day, Erisman's vehicle was located on Ruston Way, and he was found walking nearby. He was detained without incident, reportedly telling the officers, "You got me," and informing them that the gun was in his car. He later confessed to a co-worker that he had shot a woman multiple times.
Mark Allen Erisman was arrested and charged with first-degree murder, to which he initially pleaded not guilty. After evaluations determined he was competent to stand trial, he eventually pleaded guilty to second-degree murder. In May 2024, a Pierce County Superior Court judge sentenced Erisman to more than 17 years in prison for the murder of his neighbor. During the legal proceedings, it was revealed that his harassment of Perron had been ongoing for at least five years, including a previous attempt to break into her home. The tragic loss of Diane Perron, a woman remembered by her family and community as a caring and compassionate person, was a result of her neighbor's escalating delusions and aggression.
