As I have pointed out many, many times, there is no reliable way to distinguish a peaceful Muslim from a potentially violent jihadist. It isn't as if there is one sect of Islam that has renounced and rejected violent jihad and Islamic supremacism, and another that upholds such things. If that were the case, one could rely on the peaceful group and shun the group that taught violence. But contrary to popular belief, every mainstream Islamic sect and school of Islamic law teaches the necessity to subjugate unbelievers, by force if necessary, under the hegemony of Islamic law. The U.S. government, of course, denies this fact and bases numerous policies upon the assumption that the vast majority of Muslims share universally accepted notions of human rights, and abhor jihad terrorism. This is the fruit of that false assumption.
"Interpreter shoots dead two US soldiers in Afghanistan," from the BBC, January 30 (thanks to Mackie):
Two US soldiers who died in eastern Afghanistan on Friday were shot dead by an interpreter, it has emerged.
A Nato official said the translator gunned down the US soldiers before other soldiers shot him dead at an outpost in Wardak province.
A US military official told Reuters news agency the attacker seemed to be a "disgruntled employee", not a militant....
Oh, well, then it's OK.
An Afghan provincial official told Reuters the interpreter had argued with the soldiers over pay and treatment, before opening fire.
I once had a job in which I was disgruntled over pay and treatment. Oddly enough, I never opened fire.