Signs of the times.
ASL, like other languages, evolves to meet the needs of its users. On a mailing list I'm on an interpreter recently asked what the sign was for "terrorist". Sadly, she has found herself needing to use it so often nowadays that fingerspelling it has gotten to be a pain in the digits.
Nobody seems to know of one. Discussions of signs that people on the list actually used included "terror person", "terrible person", "terror group" and "awful group".
We don't get ASL interpretation of our news here. I'd be quite curious to see what professional news interpreters are using. Perhaps a common sign or combination of signs (I expect "terror person" and "terror group" will be the most useful) has emerged already.
Because it's not as if we don't need one.