Boston Police Supt. Paul McLaughlin said the incident happened shortly before 6 a.m., when officers were dispatched to 97 Mount Vernon St. after a 911 caller reported a breaking and entering in progress. The address is home to the upscale restaurant 1928 Beacon Hill. "On arrival, officers encountered a male suspect in a rear alley, armed with a large knife," McLaughlin told reporters, per video from WCVB. He said an officer discharged his taser and struck the man in an attempt to subdue him, but "to no avail."