A boxer whose bloody nose swab led to criminal charges has been convicted of robbing a Michigan credit union.
 
   Martin Tucker was found guilty Friday in Detroit federal court, along with co-defendant Quentin Sherer. They were accused of stealing $5,400 at gunpoint from Monroe County Community Credit Union in Temperance in 2009.
 
   Tucker was charged in July, a few months after the FBI acquired a discarded Q-tips swab from a boxing match in Toledo, Ohio. The bloody swab was used to match Tucker's DNA on evidence from the robbery.
 
   Tucker, a light welterweight from Toledo, is a roofer and part-time boxer. He was 1-6 in his last seven bouts before his arrest last summer.