You have a difficult situation here. You could have dialed 911 immediately after the assault, and the police would have come out and arrested the coworker and charged him with assault and a probation violation -- which would immediately put him in jail, with little possibility of being released.
The problem with that scenario, is that there may be other gang members who will retaliate against you. And, that could really get you hurt or killed.
So, you have a choice to make: you can still call the police and report the assault. If the girl will corroborate your statement, then that would seal the deal and the coworker will be arrested. If she won't, you may have a problem, because it's your word against the other employee.
Additionally, you and the girl can sue the employer for the coworker's assaut on you. But, none of that will prevent the coworker's homeys from coming after you.
If I were representing you, I would meet with you and the girl and offer to sue the employer for the assault. Then I would use that legal action as leverage to hopefully get you transfered to another location, or to have your wages paid while you search for another job, if there's no place where you can transfer.
So, you may want to think about contacting an employment rights attorney and going that route.
For a referral, see this link.
Hope this helps.
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