Columbus, Ohio (AP) -- Police say an Ohio State University janitor who shot two supervisors before killing himself was armed with two handguns and more than 50 rounds of ammunition when he walked into a campus maintenance shop and opened fire.
Nathaniel Brown had recently received a bad job evaluation and was upset over his pending dismissal.
Police said he fired nine times Tuesday morning.
Deputy chief Richard Morman said Thursday that investigators still aren't certain of Brown's motive, though they believe the shootings were work related.
It's not clear if other employees may have been targeted.
Morman says it will likely be several months before authorities complete their investigation.
The 50-year-old Brown fatally shot a supervisor in the head and neck, injured another and then killed himself.
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