I read, a long time ago, about a DEA operation in Texas that did indeed use female agents to become "girlfriends" of major drug figures. Very dangerous work, to say the least. The DEA also used a gay agent to lure a major ecstacy dealer to the US from the Netherlands just a few months ago.

Your penpal guy would have been a major figure in the drug biz for the DEA to go through that much trouble and expense to nail him.