The arrest comes 12 weeks after a VTA employee shot to death nine co-workers at the transit agency's Guadalupe rail yard on West Younger Avenue and then killed himself.
Frank Rene Lopez, 55, was arrested on suspicion of making criminal threats to a fellow trainee after failing a quiz Monday, according to a news release issued Wednesday afternoon from the sheriff's office.
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The witness told a supervisor that Lopez made the comment, "If I don't pass, I'm going to come back in here and take care of business and shoot up the place."
The supervisor contacted deputies, who responded at 6 a.m. Wednesday to the Chaboya Division Yard on South 10th Street, took Lopez into custody and booked him into county jail.
According to the sheriff's office, Lopez had made similar comments two weeks before that were not reported to the VTA or to authorities.
Lopez, who was in a training program to become a bus driver, reportedly told another trainee employee that he will "shoot up the place" if he is not hired, and then insisted he was joking around, was simply quoting a movie and should not be taken seriously.
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After his arrest, Lopez expressed remorse and requested an attorney.
The sheriff's office urges anyone with information about this incident to contact them at (408) 808-4500 or leave an anonymous tip at (408) 808-4431.