Quick Facts On David Delong: Man Behind Amber Czech's Brutal Sledgehammer Death Shows Signs Of Becoming A Serial Killer

The murder of 20-year-old welder Amber Czech has sent shockwaves through Minnesota and across the US trades community after police said she was attacked and killed with a sledgehammer by coworker David Bruce Delong.

According to NBC Chicago's report on the attack, deputies arrived at the Advanced Process Technologies facility in Cokato around 6 a.m. on 11 November, where they found Czech at her workstation with 'significant head trauma'. She died at the scene despite emergency efforts.

Authorities said surveillance footage captured Delong leaving his station, grabbing a sledgehammer and striking Czech multiple times. He allegedly confessed to the killing immediately when officers arrived. Prosecutors said Delong told investigators he had planned the attack for some time and claimed he did not like her.

The brutality, planning and targeted nature of the killing have fuelled public comparisons to serial offender behaviour, as investigators examine Delong's motives and past conduct.

Who Is David Bruce Delong? What We Know So Far

Delong, 40, was arrested at the scene without resistance. He has been charged with second-degree murder, although Wright County Attorney Brian Lutes told KARE that he will assess whether the case meets the threshold for first-degree premeditated murder. Such a charge requires convening a grand jury.

NBC's reporting shows that Delong allegedly admitted to both a witness and responding officers that he killed Czech. Court documents cited by the station noted that he believed Czech had given him 'a bad look', which he claimed upset him. That explanation has raised concern among workplace safety advocates who say the response displayed extreme volatility and hints of predatory behaviour beyond a simple dispute.

Investigators have not released additional information about Delong's history, mental state or prior workplace interactions, although early comments from prosecutors indicate they believe the attack was deeply calculated.

Industry Leaders Demand Protection for Women in Trades

The killing has intensified calls for structural reform across construction and manufacturing sites. According to Engineering News-Record's report on the aftermath, the National Association of Women in Construction and North America's Building Trades Unions urged companies to address long-standing concerns about harassment, intimidation and hostile environments.

NAWIC President Rita Brown said tradeswomen have faced unaddressed warning signs for years and that Czech 'deserved safety'. Leaders said the case reflects a disturbing pattern of threats and violence aimed at women working in male-dominated spaces.

The group stressed that employers must improve reporting systems, strengthen oversight and ensure women are not left vulnerable during early morning or isolated shifts. Czech had recently graduated from a welding programme and was beginning her career with optimism, hoping to build a future through skilled labour.

A Community Mourns a Promising Young Welder

Czech's death has drawn an emotional response from welders across the country. Messages from women in the trades filled her family's fundraising page, expressing grief and solidarity. Many described her as a rising talent whose passion for welding inspired those around her.

Alexandria Technical & Community College, where she completed her training, said she left a lasting impression through her dedication and skill. Colleagues and fellow welders said her death underscores the urgent need to protect young workers who are just starting their careers.

Amber Czech entered the field with ambition, discipline and pride. Her killing has reignited national debate about workplace safety, gendered violence and the need to recognise early warning signs before they lead to tragedy.