I saw this on the BBC and thought you should see it: Mauthausen Nazi death camp: Germany charges 'former guard' - Germany charges suspected death-camp guard
I suppose your wife's cousin was drafted and served in the Waffen-SS. Today they are sentencing Germans for the crime of being drafted and sent to a camp as a guard but not even a single one of the numerous Soviet guards in Soviet death and concentration camps was ever sentenced and never will. It should be remembered people like that former German guard were just security guards they weren't even allowed to get too close to prisoners. As a rule, the prisoners were guarded by kapos who were recruited from the prisoners themselves.
My father in law is from Timmerlaugh and 16 years younger than his oldest brother, Willhelm. Whilhem and his son heard Hitler speak in Braunschweig, Germany in 1935(?). Whilhelm's son was smitten by the words of Hitler and enlisted. Willhelm saw the folly. Similar to my own situation today with my son. FWIW, I have many friends who could be turned into the government as members of a class ruled illegal according to the laws today. I'm only one law away from me being legally complicint myself.
In 1935 and I suppose, he heard Hitler denouncing the military clauses of the Versailles Treaty and announcing the creation of the (a rather small - about half of the size of the Polish Army) Wehrmacht. It's obvious any German would be enthusiastic about it. But why he enlisted isn't that obvious, he would be conscripted anyway and why he joined the SS, the SS at the time was basically a bunch of prison/KZ guards nothing glorious in that.