Marilyn Burdick, a 62-year-old dental hygiene instructor at Mohave Community College, was murdered by her boyfriend, Louis Hugh Plunkett, who claims her death was an accident. Deadly Secrets on Investigation Discovery examines the case.
After losing her husband, Burdick met Plunkett online. The pair started dating and were inseparable for about five years until a co-worker found Burdick’s lifeless body floating in a pool on June 26, 2013.
Emergency services and officers with the Mohave County Sheriff’s Office responded to a call about a possible drowning at a home in the 5200
When they arrived at the scene, they discovered Burdick floating in a backyard pool.
Lifesaving measures were administered but to no avail. Burdick was pronounced dead at the scene.
Plunkett told investigators that the day before the incident, Burdick fell in the kitchen and hit her head on a “heavy wooden dining table or a chair and then the floor.”
He went on to say that he asked her to seek medical treatment, but Burdick refused.
The following day, while he was away for a few hours, Plunkett told officials that Burdick must have gone outside and fallen again, hitting her head and landing into the pool.
Burdick’s death became a homicide when further investigation determined that Plunkett’s account of what happened to his girlfriend did not match forensic evidence and autopsy results.
An autopsy revealed that “Burdick had a black eye, bruises to the neck consistent with strangulation, a fractured eye socket, and fractures to the spine.”
In the early hours of July 2, 2013, a detective spotted Plunkett driving westbound on Interstate 40 and tried to pull him over, but he continued driving into California.
About a half mile past the Arizona/California border, San Bernardino County sheriff deputies were able to apprehend Plunkett on multiple charges in connection to his girlfriend’s murder.
About two weeks later, he was extradited back to Arizona and booked into the Mohave County Jail.
During the trial, Deputy Mohave County Attorney Doug Camacho claimed Plunkett was in debt with a “$411,000 federal tax lien and two California state tax liens amounting to $69,000.”
According to the victim’s daughter, Karen Bender, Plunket was stealing money from Burdick.
Plunkett sent an email to Burdick, claiming to be her son-in-law. Camacho said he tried to convince Burdick to transfer her assets to him after her death and disinherit her daughter.
Camacho also showed evidence of individual retirement accounts with Burdick’s signature that was allegedly forged by Plunkett.
Although Plunkett proclaimed his innocence, in January 2015, a jury found him guilty of first-degree murder, tampering with physical evidence, and fraudulent schemes and artifices.
He was sentenced to life in prison.
In May 2016, Plunkett appealed his convictions and sentence but the Court of Appeals of Arizona affirmed both.
Deadly Secrets—The Devil’s Allure, airs at 9pm on Investigation Discovery.