Rental Property Security

[Dan Brown]

Hello Biggerpockets family!  My name is Dan and I have a couple of rental property investor friends, both residential and commercial, who have experienced trespassing and thefts in quite a few of their properties here in NJ.  As the founder of a security consulting business specializing in Healthcare facilities I've given them some pointers on some ways they could secure their properties.  My question is, is there a go to security system or method experienced rental property investors go to to secure their properties or is it just a matter of figuring it out oneself?