Incident Summary:

12/20/1971: The Cambridge Police Headquarters in Cambridge, Massachusetts, United States was bombed by a group calling itself Comrades in Arms. There were no casualties but communication equipment was damaged and two windows were shattered.



United States

North America

region/u.s. state:



Attack Information
Type of Attack (more) Bombing/Explosion
Successful Attack? (more) Yes
Target Information (more)
Target Type: Police
Name of Entity Cambridge Police Department
Specific Description Cambridge Police Headquarters
Nationality of Target United States
Additional Information
Hostages No
Ransom No
Property Damage Yes
Extent of Property Damage Minor (likely < $1 million)
Value of Property Damage Unknown
Weapon Information
Type Sub-type
Explosives Pipe Bomb
Additional Information
Suicide Attack?No
Part of Multiple Incident?No
Criterion 1 (more) Yes
Criterion 2 (more) Yes
Criterion 3 (more) Yes
Additional Information The WBCN radio station received a letter from the Comrades in Arms claiming responsibility. One month before the incident, the Comrades in Arms claimed responsibility for bombing the Honeywell Building (197111180001). A pipe bomb was discovered outside of a Cambridge bank five days before the incident (197112150003).
Perpetrator Group Information
Group Name Claimed Responsibility
Comrades in Arms Yes (Confirmed: Unknown; Mode: Letter)
Perpetrator Statistics
Number of Perpetrators Unknown
Number of Captured Perpetrators Unknown
Casualty Information
Total Number of Casualties 0 Fatalities / 0 Injured
Total Number of Fatalities 0
Number of U.S. Fatalities 0
Number of Perpetrator Fatalities 0
Total Number of Injured 0
Number of U.S. Injured 0
Number of Perpetrators Injured 0
"Police Station Blasted," New York Times, December 21, 1971.
"Group Is Taking Responsibility For Mass. Blast," Lewiston Daily Sun, December 22, 1971.