Stanley Graham was born on November 12, 1900, in Kokatahi, New Zealand. He grew up in a rural setting and later took over the Longford Hotel, managed by his father. In 1930, he married Dorothy McCoy, and the couple moved to a small dairy farm in Kowhitirangi, near Hokitika. They had two children.

Initially, Graham maintained cordial relations with his neighbors. However, by the late 1930s, financial difficulties plagued the family due to declining dairy income and unsuccessful cattle breeding ventures. These stresses, coupled with Graham's increasing paranoia and suspicion of neighbors, led to social isolation. He and his wife began practicing shooting regularly, and Graham became known for his marksmanship.

On October 8, 1941, following a dispute with neighbor Anker Madsen over alleged cattle poisoning, Graham confronted Madsen with a rifle. Constable Edward Best attempted to mediate but retreated when Graham threatened him with firearms. Best returned later with Sergeant William Cooper and Constables Frederick Jordan and Percy Tulloch. During their visit, Graham shot and wounded Cooper and Best. As Jordan and Tulloch entered the house, Graham killed them both with a single bullet. He then fatally shot Cooper as he tried to seek help. Best succumbed to his injuries three days later.

Later that day, Graham killed George Ridley, an agricultural instructor who arrived to assist the wounded. That evening, he returned home and killed Home Guardsmen Richard "Maxie" Coulson and Gregory Hutchison during a firefight, sustaining a shoulder wound himself.

A massive manhunt ensued, involving over 100 police officers and several hundred army and Home Guard personnel. Graham evaded capture for 12 days, hiding in the rugged terrain. On October 20, 1941, he was spotted near his property and shot by Constable James D'Arcy Quirke. Graham died the following morning at Westland Hospital.