FBI Special Agent Richard DesLauriers

After two bombs exploded at the finish line of the Boston Marathon in April - local, state and federal law enforcement officials went to work for five long days. The man in charge of the sprawling and fast-moving investigation was the head the Boston FBI office.

Richard — or Rick — DesLauriers became a familiar face at those press conferences April. Earlier this month, he announced that he'll be retiring from the FBI after more than 26 years. The last three of those years, he's headed the agency's Boston office, and it's been a busy time for him.

When he arrived, the FBI was wrapping up what it called, Operation Ghost Stories. DesLauriers helped direct that investigation, which ended with the arrest and deportation of 10 Russian spies, some of whom were living in the Boston area. His team also captured James 'Whitey' Bulger, after 16 years on the run. And they continued to investigate the Isabella Steward Gardner Museum heist, which remains unsolved.

But it was the Marathon bombing attacks that DesLauriers calls the most intense and challenging case of his long career. We sat down with him in his office earlier today to talk about his years directing the Boston FBI office. And we began with the events of April 15th.

Richard DesLauriers, Special Agent in Charge of the FBI's Boston office.

Check out his commencement speech as Assumption College.