What's the DEA doing in Boston?

In news footage of the manhunt for the Boston bomber on the run, I keep seeing folks in DEA jackets. Assuming DEA is the Drug Enforcement Agency, why are they getting involved in this investigation?

(Or, alternately, who is this other DEA, and what do their initials stand for?)

I just heard on MSNBC that there are some 20 federal agencies in on the operation.

The DEA has several SWAT-type teams that have the kind of training necessary for a huge manhunt operation. The Boston FBI field office is leading the investigation and taking all the manpower they can get.

So in other words, they’re probably being used as simple manpower that already are sworn federal agents and have training in apprehending criminal suspects.

Makes sense, thanks.