When Mt. Gox went bankrupt in February 2014 after a massive amount of cryptocurrency went missing from its exchange, it took about a year and a half for authorities to arrest CEO Mark Karpeles, who was suspected of falsifying account data. Investigators went as far as crunching data in servers located in the U.S.
Mt. Gox was an interesting case. The thieves on Mt. Gox simply moved money to other accounts on the exchange, it was only later that it left the exchange after that had been going on for months.