This is quite a mystery. Was this a random robbery, something personal -- or was it related to his position as director of MIT's Plasma Science and Fusion Center? Did he have a major breakthrough in clean energy? Calling Dan Brown.... Via the Associated Press:

BROOKLINE, Mass. (AP) — Police intensified their search Wednesday for a suspect in the killing of professor Nuno F.G. Loureiro at the Massachusetts Institute of Technology, two days after he was shot to death at his home outside Boston.

Loureiro, a 47-year-old physicist and fusion scientist, was shot Monday night at his apartment in Brookline, Massachusetts. He died at a local hospital on Tuesday, the Norfolk District Attorney’s Office said in a statement.

The prosecutor’s office said the homicide investigation was “active and ongoing” as of early afternoon Wednesday and had no update — earlier they had said no suspects were in custody.

The investigation into the MIT professor’s killing comes as Brown University, another prestigious institution just 50 miles (80 kilometers) away in Providence, Rhode Island, is reeling from an unsolved shooting that killed two students and wounded nine others Saturday. Investigators provided no indication Tuesday that they were any closer to zeroing in on the gunman’s identity.