Günter Hermann Ewen was born in Dillingen, West Germany, in 1962, the youngest and only son in a family of five children. From an early age, Ewen struggled with asthma, which impacted both his physical and academic development. He was known to show little academic interest, repeated two school years, and ultimately dropped out of the Hauptschule after the 7th grade. He began an apprenticeship as a paver but abandoned it due to ongoing health problems.

Ewen remained unemployed or sporadically employed throughout his 20s and lived with his parents until the age of 30. His adult life was marked by social withdrawal, financial instability, and growing alcohol dependency, which may have started as early as age 12 or 18, according to differing reports. This addiction reportedly stemmed from admiration for a sister’s boyfriend who led a reckless, hedonistic lifestyle.

Ewen had a long criminal history, beginning with theft, fraud, battery, and driving under the influence. In 1990, his behavior turned increasingly sexually deviant, including voyeurism, exhibitionism, and eventually, violent sexual assaults. In 1991, while intoxicated, he broke into a home for mentally disabled women on two separate occasions, molested them, and later that night raped another woman in her home.

In February 1993, Ewen was convicted of multiple counts of rape and sexual assault and sentenced to five years and six months in prison. A psychological assessment described him as a narcissistic individual with infantile egocentrism who disregarded the autonomy of others, especially under the influence of alcohol. While in prison, he underwent sex offender treatment and was released on parole in October 1996, after serving two-thirds of his sentence.

After release, Ewen attempted to rebuild his life by starting a small business, but in August 1998, he was accused of burglary by a friend, Robert Fisne. Though acquitted in January 1999 due to lack of evidence, the damage to his life was irreversible. During his five-month remand, he lost his business, home, relationship, and accumulated over DM 60,000 in debt. He was awarded only DM 3,000 in compensation, not enough to cover legal expenses. Ewen moved in with his sister and brother-in-law in Beckingen, helping them renovate their house in the months before his final rampage.

On May 16, 1999, 37-year-old Günter Ewen embarked on a spree killing that would claim five lives and injure eleven others before ending with his suicide two days later. The rampage began around 4:40 a.m. at the "Xanadu" nightclub in Dillingen, where Ewen opened fire into a crowd of patrons gathered outside. Two people were killed: the club manager, Roland Dekow (42), and a 40-year-old doorman. Several others were wounded before Ewen fled the scene on foot.

Just 200 meters from the club, Ewen invaded the home of Robert Fisne, the friend who had previously accused him of burglary. Inside, Ewen shot and killed Fisne, his wife Shonnette Maxine Fisne (née Joy Bogle, 41), and injured their 11-year-old daughter, Laura, who sustained gunshot wounds to the face but survived.

Ewen fled in a vehicle but crashed shortly after, then attempted to carjack multiple vehicles. One man who resisted, Étienne Kuster (39), was shot and mortally wounded. Ewen then forced a woman at gunpoint to hand over her vehicle. That car was later found abandoned near a fortified area in Sierck-les-Bains, across the border in France.

The police launched an intensive manhunt that lasted two days, involving roadblocks, helicopters, and cross-border cooperation. Ewen was believed to be hiding in a vacant military building, where shots had reportedly been heard, but the site turned out to be empty.

On May 18, 1999, Ewen was located at a hotel in Luxembourg, where he had taken his own life with a gunshot to the head. He left behind a chaotic trail of grief and trauma across Germany, France, and Luxembourg.