Okay i want to response to Taylor and Angel ... I does to agree with what Angel said that she see the deaf people that use ASL and they does to signs fast without move their mouths , yes it does to make hard for you to understand they signs to you without move their's mouth .
Am lucky really because am very good at lipreadings and i does always use BSL/SSE signers with move my mouth to use the words without voice lol .. but i does to use voice as very loud so i always control my own voice if i talk to hearing people via lipreadings on depend if they doesn't signs .. or part of signs , ( hard work lol ), I used to be BSL tutor for 11 years and now I teach BSL at work only for all the staffs at work to polish their's BSL skills .
AS for Taylor ..... you dont have to need to know fully the signers before go to your hometown deaf club. how about go on the ASL course at your area college or Adult Education College if it does have ? if you have feel the confindence enough to be brave to go Deaf club ... and you dont have to letting them know that you are the Cop . i just warning you because i does to know most deaf people does have attitude toward the Cops , i wish i could be more of help since i am not from USA smile ... and good luck ....