Eugene Walter Barrett was born on June 30, 1931, in Oakland, California. He was the older of two sons in his family, with his parents being Howard and Emily Barrett. Growing up, not much is known about his early years, but it is clear that he did not have a stable path in education. Eugene attended Washington Intermediate School in Honolulu, but he dropped out in the ninth grade. This decision marked a turning point in his life, and he faced challenges as a young adult without completing his education.

After leaving school, Eugene opted to join the Army. He served as a soldier during the Korean War. However, his military career did not go as planned. In 1955, he was dishonorably discharged due to his excessive drinking. This event likely impacted his future relationships and choices, leading him down a troubled path. His time in the service did not seem to provide the discipline or direction that could have set him on a better course in life.

Following his discharge, Eugene returned to Honolulu. It was there that he began a romantic relationship with Annie E. Phillips, a divorced mother with five children. During this time, Eugene worked as a house painter, but he struggled to maintain steady employment. His drinking problem worsened, which ultimately contributed to the end of his relationship with Phillips in 1959. When Annie decided to break things off with him, Eugene was unable to cope with the rejection. He became increasingly angry and focused on thoughts of revenge.

Eugene’s childhood experiences, along with his turbulent army service and troubled relationships, may have shaped his unpredictable behavior. His life would take a serious turn after his breakup with Annie. He armed himself and confronted her at her home. This confrontation would change the course of his life forever, as it marked the beginning of a violent chapter. Barrett's struggles with alcohol and his inability to cope with rejection fueled his descent into violence, leading him to make choices that would have devastating consequences.

Eugene Walter Barrett was born on June 30, 1931, in Oakland, California. He was the older of two sons born to Howard and Emily Barrett. Not much is known about his early life. He attended Washington Intermediate School in Honolulu but dropped out in the ninth grade. After leaving school, he joined the Army and fought in the Korean War. However, his time in the military ended poorly when he was dishonorably discharged in 1955 because of his drinking problems.

After leaving the Army, Barrett returned to Honolulu, Hawaii. There, he began a relationship with a woman named Annie E. Phillips, who was a divorced mother of five. During this time, Barrett struggled to keep a job as a house painter and continued to drink excessively. Annie eventually ended her relationship with him in 1959 because she could no longer deal with his behavior. Unable to cope with the loss, Barrett became furious and decided to murder her.

On the day of the murder, Barrett armed himself with a gun and took a bus to Annie's apartment complex, Mayor Wright Homes. He forced his way inside her apartment and found her in the bedroom with her youngest child. Without giving her a chance to react, he shot her multiple times, killing her instantly. The noise of the gunfire shocked Annie's children, who were watching TV. Neighbors heard the commotion and managed to subdue Barrett until the police arrived. During his trial, Barrett claimed he could not remember the shooting because he was drunk. However, witnesses said he expressed that Annie "deserved it." The evidence against him was overwhelming, and he was sentenced to life imprisonment.

In 1967, Barrett’s sentence was commuted to a minimum of 15 years, and he was paroled after serving eight years. Following his release, he married Roberta Ululani Aveiro in 1971, but their marriage did not last long. Roberta filed for divorce in 1972, citing Barrett's excessive drinking. Just a month after the divorce filing, Barrett committed his second murder. On December 27, 1972, he attacked Roberta with a kitchen knife in her hotel room and stabbed her multiple times. He pled guilty to a reduced charge of manslaughter and was sentenced to 10 years in prison. He was paroled again in 1976.

For the next several years, Barrett lived quietly in Honolulu, but he continued to drink heavily. One of his neighbors was Doneshia "RoxAnne" Kastner, a woman who had a difficult life and faced issues of substance abuse. Although there was no confirmed relationship between them, Barrett believed that Kastner was mocking him for dating other men and behaving inappropriately. After struggling with his emotions, Barrett voluntarily admitted himself for psychiatric treatment in mid-1995.

Once he was released from treatment, Barrett discovered that Kastner had moved to a nearby apartment. This news sent him into a rage. On August 11, 1995, just days after his release, Barrett spent the day drinking with friends. When he saw Kastner return home, he went back to his apartment, retrieved a .25 caliber pistol, and went to her apartment. He shot her twice in the head as soon as she saw him. Kastner's young son witnessed the shooting and immediately called for help.

The police quickly found the gun, which had been reported stolen years earlier. An arrest warrant was issued for Barrett, but he voluntarily surrendered the next day at a local inn. He was charged with murder, theft, and unlawful possession of a firearm. During the preliminary hearings, Kastner's young son testified against Barrett, providing crucial evidence in the case. After his arrest, Barrett expressed a desire to remain in jail while he dealt with his issues.

At the trial, his lawyer claimed that Barrett's actions were due to Kastner's supposed mistreatment, causing him to snap. Despite his claims, the jury found Barrett guilty of murder, and he received an automatic life sentence. The judge also mandated that he serve at least 40 years before being eligible for parole.

After the trial, Barrett was transferred to an out-of-state prison in Oklahoma. In 2003, he was returned to Hawaii due to declining health. He was admitted to Pali Momi Medical Center, where he passed away from an undisclosed illness on November 8, 2003. Barrett was remembered as a prominent figure in Hawaii's criminal history, being one of the few confirmed serial killers known to have operated in the state.