Mark Mangaccat, born in 1986, was a dedicated Filipino immigrant from Daly City, California, who worked tirelessly at the San Francisco International Airport (SFO).

He and his fiancée, Thandar Seinn, originally from Myanmar, had a young son and were driven by the ambition to secure a stable, comfortable future.

After years of sharing a home with Mark’s parents and saving diligently, the couple planned to relocate to Las Vegas on April 27, 2018, where the cost of living was lower. They were scheduled to marry once they settled into their new life.

Mark’s life intersected tragically with Kevin Prasad, a 35-year-old security guard who also worked at SFO. Prasad, though known as an educated individual, harbored a consuming, secret crush on Seinn.

Despite Seinn being engaged, Prasad pursued her, initially using work-related texts before his messages grew explicitly romantic. Seinn testified she did not reciprocate his feelings and informed Mark about the inappropriate advances.

Mark, confident in their relationship, dismissed Prasad’s interest as harmless. However, when Seinn submitted her resignation, the news that she was leaving the Bay Area with Mark pushed Prasad over the edge.

His infatuation quickly curdled into jealous rage. Authorities later found records of Prasad expressing desperation, telling Seinn he could offer her and her son a better life than Mark could. When she firmly rejected his final offer, Prasad decided to eliminate his rival.

Prasad enlisted his friend, Donovan Rivera, 25, to assist him. Rivera, who had known Prasad for years, drove the getaway car. Prasad initiated his plan on April 25, 2018, just two days before Mark and Seinn’s planned departure.

After Seinn finished her final shift, Mark picked her up, a routine the assailants had likely observed. Prasad and Rivera allegedly tracked the couple’s vehicle from SFO back to Mark’s parents’ home in Daly City.

As Mark slowly backed the car into the garage, Prasad, who had been lying in wait, emerged. He approached the driver’s side and quickly fired a weapon multiple times, striking Mark and causing his immediate collapse.

The tragic incident was swift. Seinn was in the passenger seat when Mark was fatally wounded. Prasad and Rivera fled the scene in their vehicle, using it as their getaway transport.

Seinn, in shock, immediately called for help. Mark was rushed to a medical center, but he succumbed to his injuries. Seinn informed the police about the obsessed co-worker, providing the crucial lead that focused the investigation on Prasad.

The investigation confirmed the conspiracy. CCTV footage and cell phone records showed Prasad and Rivera tracking Mark and Seinn’s vehicle from the airport to the home. This established the premeditated nature of the crime.

During interrogation, both suspects implicated each other. Rivera claimed he was unaware of Prasad’s intent until the moment he fired the weapon, while Prasad eventually admitted his infatuation with Seinn was the motive.

The prosecution argued Prasad’s intent was to remove Mark, then step in as the comforting figure to win Seinn’s affection—a devastatingly manipulative plot.

In 2023, after a one-week trial, Kevin Prasad was found guilty of first-degree taking of a life with special circumstances. Donovan Rivera was also found guilty on related charges for his role as the accomplice.

The judge sentenced Prasad to 25 years to life in prison. The tragic end of Mark Mangaccat, a devoted father and fiancé, was the result of a co-worker’s consuming, unrequited love.