u/ContributionHappy879

My 85 year old parents keep having punk boys (teenagers who know better) come up their walkway and then BANG as hard as they can on their front door at 2am. This happens OFTEN and I'm sick of it and want to do something. Is there an outdoor security-type system where I can put two laser beams (one on each side of their walkway) that once it is tripped, it will emit a loud siren OUTSIDE to scare them off? I don't need it to alarm INSIDE because that doesn't help scare these punks off. Any help or websites/companies that you can point me in the right direction? I am not a good DIYer so unless it's easy, I won't be able to McGyver-it myself. :) THANK YOU for any help!!!!