Some from that and many more are former FARC and ELN members. And since FARC acted as muscle for the drug gangs I doubt that many were on the other side.

As part of the peace negotiations that have been going on since 2012 FARC agreed in 2014 to get out of the drug business. Since then FARC has made a show of doing that. But the head of the Colombian anti-drug police points out that FARC presence is still being found when drug operations are raided. FARC leaders insist that these are renegade FARC members but the evidence on the ground says otherwise.

http://strategypage.com/qnd/colombi/articles/20160507.aspx

Is this where Americans Federal money is spent?

I don't think Americans should pay their Federal money on any Colombian bombs or jets or drug war.

.....something the police appreciate because the drug gangs often operate in large armed groups that sometimes outnumber and outgun the police sent to get them in remote areas.

or "forward operating base" from which the US can launch operations in any direction in the Americas.

Really sad situation.

Over $10 billion have been dumped into Colombia since 2000, and the start of Plan Colombia, and the people, themselves, are NOT one bit better off, of course, but the government has been wildly corrupt, so many politicians connected to paramilitary death squads, which they have used for assassination of opponents, or coercing votes in their districts, or driving people off their lands so the land can be given to corporations, etc., etc. and only during Santos' Presidency has the government actually been engaged in putting any of these freaks in prison. Now there are many, MANY right-wing politicians in jail, but not nearly as many as there should be.

Corrupt, awful, deadly military and government, and the US wants to keep Colombia under its control for use both as a military ally, and as a resource to be used by US corporations for cheap labor, working hard endlessly, no benefits, very low wages. Bleak picture for the human beings unlucky enough to have been born there, with no wealthy relatives, and no second homes in Florida, where they can go stay if they want a bit of a change, like wealthy fascist oligarchs in the Americas.