The Secret Service office in Boston is a 2 mile drive from MIT. Once you decide to bring in the police, it makes sense that they'll contact specialist law enforcement that focus on computer crimes, especially since the Secret Service is so close.
Per his own LinkedIn [1], Michael Picket, the Secret Service agent, is a member of the New England Electronic Crimes Task Force Forensic Laboratory. Their website [2] has long role for the lab, but it a) supports local law enforcement (like Cambridge PD), and b) includes seven area universities (Harvard, Dartmouth, and Babson are the three mentioned; MIT was not, but doesn't necessarily exclude them).
My guess is it wasn't so much the Secret Service getting involved, but this DHS agency mandated by the USA PATRIOT act [3] made themselves available to major local organizations. Wouldn't be surprised if ECTF spent its first couple of years just meeting individual orgs one at a time for meets/greets.
"Have a computer crime that isn't just your usual Craigslist scam? Give Mike over at the Boston ECTF a call, and he can help you out."
If I were a USSS officer specializing in computer crime and MIT called me after discovering a laptop that was used in an ongoing crime, I'd run like hell because I wouldn't want decisions to be made by the local Cambridge cops since they don't know anything about computer crimes. I mean, if you think the laptop represents a crime scene, you really don't want non-specialists handling it right?
If MIT does research related to military/defense technology, the possibility that such information was involved is probably enough to get the Feds interested, especially in the beginning.
