Michael MacQueen hunts war criminals for a living.

And, after nearly 10 years of tracking down the Balkan war criminals who often hide in plain sight in the U.S., the only Balkans-region historian for U.S. Immigration and Customs Enforcement is retiring ‘imminently,’ according to ICE (the agency would not release a specific date).

The historian pulls together the scraps of a Balkan war from more than 20 years ago—sometimes finding records of war crimes written on old scrap paper, in children’s elementary school notebooks, in military or police records or by interviewing concentration camp survivors as witnesses—anything to track down the widely forgotten war criminals of the conflict that tore apart the former Yugoslavia in the 1990s.

Systematic rape, sexual enslavement, torture, random killings and concentration camps where prisoners were starved and beaten are among the atrocities committed during the Bosnian War, an attempted ethnic cleansing of Bosnian Muslims lasting from 1992 to 1995, in which some 100,000 people were killed or died of war-related causes. Millions were displaced.” (Full story at Newsweek)