Need help with good frequencies for a security team!

[TangoEchoGolf]

Hi, I am located in cass county, MO. I do church security and I am in need of some good frequencies to use. The main radio the team uses is the Baofeng BF-888s and I personally use the UV5R. We need something that will work well through brick walls and auditoriums and be legal, plus we need as little interference as possible. I'm still learning about this stuff. Would CTCSS help with the interference?

 

[DHAS12]

I believe MURS frequencies would work

https://www.fcc.gov/wireless/bureau-divisions/mobility-division/multi-use-radio-service-murs

*edit* after doing a bit of research. The baofengs are not legal on murs because they are not fcc certified.