Army SSG John Diamond Convicted of Murder of Air Force Capt. Frank Theer; Military Court Sentenced to Life in Prison, No Parole (August 28, 2001)

Michele Theer photo

John Diamond, US Army

Army SSG John Diamond, 28, was accused of fatally shooting Air Force Capt. Frank ‘Marty’ Theer in Fayetteville, North Carolina on December 17, 2000. Capt. Theer and his wife Michelle were on their way to a Christmas party when Michelle claimed she needed to stop at her place of employment. After waiting for awhile, Capt. Theer exited his vehicle to check on Michelle. As he ascended the stairs at the office building, he was shot multiple times and died at the scene. The Fayetteville Police Department launched a homicide investigation and would learn that Michelle Theer was having an affair a married Fort Bragg Army Ranger named John Diamond. It was later theorized that psychologist and Air Force Reservist Michelle Theer was the mastermind behind the murder of her husband. She was accused of setting Capt. Theer up when she lured him to her office; she was also accused of manipulating SSG Diamond to commit the murder. The prosecutor’s theorized the motive for the homicide of Capt. Theer was the Servicemen’s Group Life Insurance money.

During the investigation, the police got a tip that a gun matching the murder weapon was in the custody of SSG Diamond which connected him to the crime. Conveniently, SSG Diamond admitted to having a gun that fit the description of the one used in the murder but he claimed his vehicle had been broken into and the gun was stolen. SSG Diamond was arrested by the US Army for having an unregistered weapon on a federal installation while they investigated his role in the murder. They would learn that despite his marriage status, he was in love with Michelle Theer and would do anything for her. The military courts charged SSG Diamond with first degree murder and on August 28, 2001, a six-member military panel at Fort Bragg found him guilty; Staff Sgt. John Diamond was sentenced to life in federal prison. Michelle Theer disappeared by the time the civilian authorities caught up with her but she was eventually located in Florida living under an assumed identity. Michelle Theer was convicted of conspiracy to commit first degree murder on December 3, 2004 and sentenced to life in prison, no parole.

Investigation Discovery:

In 2000, Michelle Theer was an Air Force wife in the military town of Fayetteville until a fatal shooting made her a widow. The investigation into her husband’s death led police to the door of an Army Ranger – taking orders from very unlikely accomplices. -Fayetteville, Sins and Secrets (S2,E3)

Sexy psychologist and doting Air Force wife Michelle begins a swinging affair with Army Sgt. Diamond while her husband, Captain Marty Theer, is away. But all’s fair in love and war, and Marty’s return will remind them that love is a battlefield. -Sergeant Swinger, Scorned: Love Kills (S4,E1)

Oxygen:

A frantic, distraught woman runs into a video rental store screaming that her husband has been shot. -Michelle Theer & John Diamond, Killer Couples

Killer Couples: S8 E5 Preview – Michelle Theer and John Diamond | Oxygen

Killer Couples: S8 E5 After the Verdict – Michelle Theer and John Diamond | Oxygen

Psychologist Debbie Layton-Tholl talks about her experience meeting with Michelle Theer. -Michelle Theer & John Diamond, Killer Couples

A lonely military wife and psychologist go searching for sex on the Internet with deadly results. -Michelle Theer & John Diamond, Killer Couples (S8,E5)

Editor’s note: With a cable subscription, you can download the free ID Go app and watch Investigation Discovery programming at your convenience. And for those who do not have cable, you can watch “unlocked” episodes on the ID Go app including the latest premieres. For those who prefer commercial free programming during your binge session, Prime Video has an ID channel: ‘True Crime Files by Investigation Discovery” available for $3.99 a month. It’s a compilation of older seasons but totally worth the cost if you are a true crime addict. Download the ID Go app or purchase ID True Crime Files & binge away.

Related Links:
Website: Free John Diamond
Staff Sgt. John Diamond | The JAG Hunter
Wife of Slain Soldier Charged with Murder
Makeover Madness | People Magazine Investigates
Conviction of pilot’s wife in killing upheld
United States v. Staff Sergeant John M. Diamond (2007)
Investigator: Did Michelle manipulate for murder?
Witness: Did Michelle manipulate for murder?
John Diamond vs United States of America (2010)
Convicted killer wants prison to stop censoring his racy letters
Sinclair Takes His Legal Battle Online
Michelle Theer case featured on ‘Killer Couples’
Psychologist Michelle Theer, Her Internet Affair With John Diamond, and the Murder of Air Force Captain Marty Theer
On the Firing Line | Military Corruption
Army Wives: The Unwritten Code of Military Marriage | Tanya Biank
Cyber Reconnaissance, Surveillance and Defense | Robert Shimonski
Murder Along the Cape Fear: A North Carolina Town in the Twentieth Century | David Morgan
The Officer’s Wife: A True Story of Unspeakable Betrayal and Cold-Blooded Murder | Michael Fleeman
Fayetteville | Sins and Secrets | Investigation Discovery (S2,E3)
Fayetteville | Sins and Secrets | Investigation Discovery (website)
Fayetteville | Sins and Secrets | Investigation Discovery (Amazon)
Sergeant Swinger | Scorned: Love Kills | Investigation Discovery (S4,E1)
Sergeant Swinger | Scorned: Love Kills | Investigation Discovery (website)
Sergeant Swinger | Scorned: Love Kills | Investigation Discovery (Amazon)
Killer Couples: S8 E5 Sneak Peek – My Husband Has Been Shot! | Oxygen
Killer Couples: S8 E5 Preview – Michelle Theer and John Diamond | Oxygen
Killer Couples: S8 E5 After the Verdict – Michelle Theer and John Diamond | Oxygen
Killer Couples: S8 E5 Bonus Clip – Michelle Was Villified by the Media | Oxygen
Michelle Theer & John Diamond | Killer Couples | Oxygen (S8,E5)
Michelle Theer & John Diamond | Killer Couples | Oxygen (Amazon)
Air Force Capt. Frank Theer Murdered by Unidentified Gunman; Wife Michelle & Army SSG John Diamond Sentenced to Life in Prison (December 17, 2000)
Former Air Force Reservist Michelle Theer Convicted of Murder of Husband Frank Theer; Sentenced to Life in Prison, No Parole (December 3, 2004)
Sins and Secrets Premiered ‘Fayetteville’ on Investigation Discovery: Michelle Theer & John Diamond Left a Permanent Mark on Community (January 26, 2012)
Scorned, Love Kills Premiered ‘Sergeant Swinger’ on ID: Air Force Captain’s Murder Reveals Wife’s Evil Intent, Adultery & Greed (October 4, 2014)
Killer Couples Premiered ‘Michelle Theer & John Diamond’ on Oxygen: Affair Leads to Murder of Air Force Capt. Marty Theer (September 3, 2016)
Scorned, Love Kills: 6 Active Duty Military Homicide Cases Featured on Investigation Discovery

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s