On December 18, 1996, Marcelo Kenji Yoshino, 22, an employee of the Sao Paulo State Sanitation Company, entered the offices where he formally worked with a Glock 9 mm pistol hidden in a gift package.

Once inside, he looked for the object of his obsessive and unrequited passion -- co-worker Valeria Lellis -- and opened fire, killing three women and wounding two men.

Six months previously Yoshino had been transferred to another unit of the company because of his stalking and harassment of Valeria. He was also sent to a psychologist, but continued frequenting his former office to visit her.

On the fateful payback day, Marcelo hunted down Valeria and fired at ten coworkers killing her, their supervisor, and another woman, and wounding two men. After the rampage, the obsessive coworkers shot himself in the head.

Mayhem.net