Ted Maher was born on June 9, 1958, in Auburn, Maine. He grew up there and also lived in California for a time. When he was 12 years old, his family moved to Upstate New York. Ted enlisted in the U.S. Army in the mid-1970s and became a Green Beret. After his service, he focused on his education and earned nursing degrees from Dutchess County Community College and Pace University.

Ted had a brief first marriage that resulted in one son. While attending Dutchess County Community College, he met his third wife, Heidi Wustrau. The couple lost touch for around two years but reconnected in 1991. Both were attending Pace University and working at Columbia Medical Center of New York Presbyterian Hospital at that time. They got married on December 12, 1993, and had two children together. The family settled in Stormville, New York.

During his time as a registered nurse, he worked in the neonatal unit at the Columbia Medical Center. While there, he found a camera left behind in a patient’s room. He developed the film and returned it to the camera’s owners, Laura and Harry Slatkin, who were grateful to have pictures of their newborn twins. Harry Slatkin later offered Ted a unique job opportunity. This led Maher to an interview with a personal assistant to Edmond Safra, a wealthy banker in Monaco. Safra needed private nursing care for his health issues.

The Safras appreciated Ted's background as a Green Beret and believed he could serve as both a bodyguard and a nurse. They offered Ted a contract at an impressive pay rate of $600 per day. With financial pressures from a hospital strike and legal issues related to his son, Ted accepted the job and moved to Monaco in early August.

On December 3, 1999, a fire broke out in the penthouse apartment of Edmond Safra, a billionaire banker who was suffering from Parkinson's disease. At that time, Theodore "Ted" Maher was working as a nurse for Safra. He had been assigned to the overnight shift alongside another nurse, Vivian Torrente. Maher later claimed that two intruders had entered the apartment. He said he fought them off and got injured in the process.

In an attempt to alert others about the supposed attack, Maher lit toilet paper in a trash basket to trigger the smoke alarm. While he went to the lobby seeking help, police and firefighters were not able to reach Safra and Torrente until it was too late. After the incident, Maher initially maintained his story about the intruders. However, days later, Monaco's chief prosecutor revealed that Maher confessed to starting the fire intentionally to get attention and admitted that his injuries were self-inflicted.

During his trial, Maher acknowledged that he had set the blaze. He claimed he never intended for it to escalate into a deadly situation. Maher explained that he wanted to impress Safra to secure a more prominent position. The prosecution argued that he had allowed the fire to spread, leading to the deaths of both Safra and Torrente.

In December 2002, Maher was convicted of arson in the deaths of Safra and Torrente and was sentenced to 10 years in prison. Just a few weeks after his sentencing, he attempted to escape from prison but was caught shortly after. Following his release in 2007, Maher maintained his innocence and claimed that he had been coerced into confessing during his hospitalization after the fire.

In June 2022, Maher was arrested in Texas on charges unrelated to the prior incident, which included kidnapping search and rescue dogs owned by his ex-wife.