Lead prosecutor William Weinreb delivers opening statements Wednesday at the Moakley U.S. Courthouse while 21-year-old Dzhokhar Tsarnaev sits between his attorneys. Tsarnaev could be sentenced to death if convicted.

A MakerBot 3D printer prints plastic parts during the hackathon.

Sam Creighton performs with Northeastern University’s premier co-ed a cappella group, the Nor’easters, which took first place at the ICCA Northeast Quarterfinals on Saturday.

A team works on their project during the hackathon.

The MIT Undergraduate Energy Club hosted the 2015 Energy Expo on Thursday in Lobdell. Students networked with representatives from energy companies.

The lower floor of the hackathon in Lobdell.

Jack Erdozain ‘17 uses a dremel to modify an electric motor mount.

The bridge connecting Buildings 12 and 24 was removed on Saturday in preparation for the demolition of Building 12.

A community gathering in memory of Matthew L. Nehring ’18 was held in the Memorial Lobby of Building 10 on Tuesday night. President L. Rafael Reif addressed the attendees.

Kevin Wang ’16 reaches for a volley on Friday’s men’s tennis match against UMass Boston. MIT defeated UMass Boston 9-0.

One of the participants grabs a quick nap during the hackathon.