A Cambridge man who at one time was in possession of the gun that the Boston Marathon bombers used to kill MIT police Officer Sean Collier has pleaded guilty to related charges.
Merhawi "Howie" Berhe pleaded guilty Thursday in federal court to possession of a firearm with an obliterated serial number.
Sentencing was scheduled for June.
Prosecutors say Berhe gave the gun to Stephen Silva, who later gave it to convicted marathon bomber Dzhokhar Tsarnaev. Prosecutors did not allege Berhe had advance knowledge of the marathon attack.
Tsarnaev and his older brother, Tamerlan, used the gun days after the April 2013 bombing to kill Collier in an attempt to steal his weapon.
The older brother was killed in a confrontation with police.
Silva previously pleaded guilty to related charges.