I used a standard home video camera connected to a domestic recorder set to run in long play. That gave me 8 hours of good quality tape and enabled the police to nick the old b*****r that was vandalising my car on a public highway. The tapes went through the police and several solicitors and at no time did anyone say I shouldn't have been filming.
To round the story off, the old boy ( 70+ yrs old! ) was arrested and marched off to the nick. CPS decided that there was insufficient evidence to prosecute ( !! ) despite the fact that you could hear the key on the metal for several seconds and see the bloke - who admitted it was he - but he denied scratching the car and the video did not actually pick up his hand against the bodywork.
The insurance co started proceedings against him and after 2 years of letters the old boy stopped replying. At that point the NU dropped the case. I could sue him privately to get my £120 excess back but to be honest it isn't worth the hassle. I don't think he'll do it again.
TonyB