Why does this need to be reported to the police, can't someone just send them a link to the video so they can prosecute for injuring the rider of the horse?
None of the stuff you talk about is on film, sound has been cut, you are breaking the law yourself to catch her... 2 wrongs dont make a right. You also back off when she started filming. bit fishy.
How were they "acting suspicious"? The problem with reports like this mate is their lack of detail. Where did this occur? Why are they a nonce? If you are genuinely concerned please contact the police first.
Possibly the worst driver I've ever seen. Charging down the wrong lane and cutting people up. Actually saw one guy get out of his car and threaten him as he nearly caused an accident stay clear of this driver!
It's the rider that fell off the horse that I feel sorry for. Hopefully this vile woman will be in prison soon.