You could start here to find out how many times the HS has called the police. It doesn't tell you if there is gang activity, but it gives you some idea of the types of problems the school has:
http://www.montgomeryschoolsmd.org/departments/sharedaccountability/safetyglance/index.aspx
I would look into QO or RM. Someone posted a link to a graph that showed each HS's FARMS/racial breakdown, and these two HSs were right in the middle. Good mix of everyone. On the far right, you had the W schools, mostly white/low FARMs... hm.. just a coincidence it's on the far right? OK, I'm reading too much into it.
FWIW, we chose not to buy in one of the W clusters. While these schools are rated well, they have their own issues, mostly surrounding issues that come from too much wealth. I didn't want my kids around that kind of atmosphere, either.