I need help reformatting a video of my car crash

I was hit by a speeding car was had my ride totaled. I got an accident attorney and she told me to get anyfootage of the accident. I was able to get security footage from a mcdonalds. The mcdonalds manager was cool and gave me a copy of the video (he told me to get a usb drive and he'll save the securuty footage from their work computer) the problem is when I put the video on my mac it was in some weird cctv format and I couldnt even play the video. If anybody can please help me I would appreciate it