Because he loved animals

We are all familiar with Whitey Bulger, the godfather of Boston's Irish mafia, who was arrested in Santa Monica this summer, after 16 years of hiding.

Why was he caught?

Because he loved animals

Bjornsdottir took notice of the attention the couple routinely paid to an abandoned, tiger-striped cat in the neighborhood, and eventually grew close (or at least closer than most) to Greig [Whitey's girlfriend]. It was that bond, over the cat, that ultimately led to the fugitives' capture, according to the paper.

[...]

she saw a CNN report on the FBI’s latest effort to track the 82-year-old Bulger and his 60-year-old girlfriend, Catherine Greig. Bjornsdottir recognized them immediately as the Gaskos, her former neighbors—Tiger’s benefactors—an ocean away on Third Street.

More at: http://slatest.slate.com/posts/2011/10/10/james_white_bulger_former_miss_icleand_anna_bjornsdottir_was_fbi.html