Michael Robert Ryan was born on 18 May 1960 in Savernake Hospital, located in Marlborough, Wiltshire. He was the only child of Alfred and Dorothy Ryan. Alfred, his father, worked for a local government agency as a building inspector and lived until he was 80, passing away from cancer in 1985. Dorothy, his mother, held jobs as a school dinner lady and later as a waitress at the Elcot Park Hotel.

Michael grew up in Hungerford and attended Hungerford Primary School first. After that, he moved on to John O'Gaunt School. When he turned 16, he continued his education at Newbury College. However, he dropped out before completing his studies. It is said that, for a time, he worked as an antique dealer, but this detail is not confirmed by official reports.

On 7 April 1987, Ryan started a job as a laborer through a Manpower Services Commission scheme with Newbury District Council. He worked on footpaths and fences, including areas by the River Thames in Reading. This employment lasted until 9 July 1987 after which he ceased working and began to claim benefits.

At the age of 18, Ryan was issued a shotgun certificate, allowing him to own weapons legally. He showed a keen interest in firearms and later applied for a firearm certificate in December 1986. This license granted him permission to own two pistols, and he continued to add more firearms to his collection in the months that followed. By the time of the tragic events in August 1987, he held licenses for eight firearms. Throughout his life, he maintained a fascination with firearms and often practiced at shooting clubs.

On August 19, 1987, Michael Ryan drove to Savernake Forest in Wiltshire with several firearms in his car. At around 12:30 PM, he approached a woman named Susan Godfrey and her two young children. He held her at gunpoint, led her into the forest, and shot her 13 times.

After leaving the forest, Ryan stopped at a nearby petrol station, where he shot at a cashier but could not fire successfully at close range. He then drove back towards Hungerford, arriving at his house around 12:45 PM. Once inside, he shot his family's two dogs before leaving again with ammunition and weapons.

Outside, he shot and killed his neighbors, Roland and Sheila Mason, before injuring a 14-year-old girl nearby. He then wounded another local woman and continued his spree by killing Kenneth Clements, who was walking his dog with his family. As the police began to respond to multiple reports of gunfire, Ryan confronted an unarmed police officer, Roger Brereton, and shot him. Brereton died while attempting to report the shooter.

Ryan continued his attack, firing at nearby civilians, including a mother and daughter in a car. He shot and killed George White as White returned home. Ryan then shot 84-year-old Abdur Khan in his garden. As the police surrounded the area, Ryan killed several more individuals, including taxi driver Marcus Barnard and Douglas Wainwright, who was visiting his son.

Ryan went on to shoot and kill Sandra Hill while she was driving and later forced his way into a home, where he killed Jack Gibbs and mortally injured his wife, Myrtle. As the situation escalated, police helicopters arrived and broadcast warnings to the public while Ryan shot at the helicopters.

He took refuge in a closed school as police tried to contain him. Several attempts were made to negotiate with him, during which he expressed regret and acknowledged the chaos he had caused. At around 6:52 PM, after a period of silence, he shot himself in the head. By the time the police gained access to the school, Ryan was dead, ending his deadly rampage that left 16 people, including himself, dead.