Eric Stanley George Graham was born on November 12, 1900, in Kokatahi, on New Zealand’s West Coast. He was raised in a rural setting where his father, John Graham, operated the Longford Hotel, built in 1902 approximately ten miles from Hokitika. It was here that Eric gained early work experience during his childhood. In the late 1920s, he met Dorothy McCoy, a young woman who had moved from Rakaia to work at the hotel. The couple married on December 22, 1930, in Christchurch. After a brief stay in the city, they relocated to a small dairy farm in Kowhitirangi, where they raised a son and a daughter.

Initially, Graham maintained cordial relations with his neighbors. By the late 1930s, Graham faced growing financial strain. His dairy business suffered losses due to cream being condemned by the Westland Co-operative Dairy Company, and a failed attempt to breed cattle left him more than £550 in debt. 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.

By 1941, tensions with local authorities had escalated. Police had requested his .303 rifle be handed over for the war effort, which he eventually did on July 15. However, the Grahams retained other weapons. Then, on September 11, Dorothy Graham purchased a 7mm Mauser rifle and ammunition for her husband from a department store in Christchurch.

On October 4, he accused neighbor Anker Madsen of poisoning his cattle. When Madsen reported this to Constable Edward Best, the officer initially refrained from action in the hope that tensions would subside. 

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. 

Following the rampage, Graham fled into the surrounding bushland armed with multiple weapons, including the 7mm Mauser, two Winchester rifles, the .303 previously seized from another local, and a Colt .32 revolver stolen from Sergeant Cooper.

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. He was buried at Hokitika Cemetery.