Great question. I would recommend you search the City of Brentwood Police department website.
They have a really cool crime mapping tool - you can search by types of crimes (burglary, auto theft, etc.) Brentwood has a few gated communities, but Deer Ridge is not one of them. Deer Ridge is a lovely community with a public golf course meandering through it. If you need assistance locating the gated communities (for families or 55 and older) please feel free to give me a call. (925) 766-3791. I am an area expert. Take care and happy house hounting!!