Googling 301-804-4700 brings up Security Industry Association in Silver Spring, Maryland; 4701 is their fax number. There's a listing of employees with direct phones with numbers up to 4717, missing only 4712, and then a few random higher numbers (20s and 40s). The page is copyrighted 2013. Make of that what you will.
I just got a call from this number here in Calgary. Didn't recognize it so let it go to voice mail. They didn't leave a message, so I assume it's a scam.