"From my personal experience, this man once assaulted a foreign teacher with an empty beer bottle"

This is completely false. First of all, this is not from YOUR "personal experience" as you were most certainly not present at the time of this incident. Only 6 people were present at the time, myself included.
I have been working at Owen College for Owen Buckland (the ONLY owner - past and present - of Owen College) for 3 and half years. Owen owns the college but does not manage it. Management has changed hands 3 times since I began at the college in 2005 and I will concede that previous managers have been seriously lacking in both skills and experience. However, our most recent manager (who took over the role in March of this year) is absolutely fantastic and we are all looking forward to a long and happy future together. He brought with him a team of staff who have been working together for several years and our current team of teachers has been in place for more than a year and will remain so for quite some time to come.
The previous manager (the one involved in the "incident" I referred to earlier) DID NOT assault a foreign teacher with anything. The foreign teacher in question had previously been employed at the school but was asked to leave because of a drinking problem and he was unable control his temper in the classroom, upsetting many students.
At the time of the incident, the "teacher" was unemployed as other schools had also hired and subsequently fired him for the same reason. He had been asked repeatedly to stay away from the college as he had been harassing several of our female students. He had also taken to carrying a large stick around with him and threatening people with it. He had followed one of the girls to the school, shouting and threatening (the girl was in tears), and our previous manager stepped in to diffuse the situation. The FOREIGNER assaulted our manager by shoving him against the school bus. Our manager was simply preparing to defend himself when he picked up the empty bottle but he NEVER touched the foreigner. Thankfully, the problem was resolved without any further incident.
As mentioned before, I have been working with Owen for three and half years and have no intention of severing that association in the foreseeable future. I have no hesitation in recommending him as an employer and will happily provide a reference or further information to anyone interested in working for the Buckland Group. Owen will provide my email address (upon request) to any new applicants. Anyone doubting my foreign ethnicity is welcome to check both the Owen College and Buckland websites for current teacher photos and profiles.