In a memorandum sent by General Sir John Maxwell to the then British Prime Minister, Herbet Asquith, the following description was provided for Con Colbert:

This man was one of the most active members of the Sinn Fein organisation. He was a associate with all the leaders and took a prominent part in the organisation of the rebel army in which he held the rank of Captain. He was armed at the time of his surrender and came from the neighbourhood of houses from which heavy fighting had taken place earlier in the day.

Con Colbert was tried by Field General Courts Martial on 4 May 1916. The proceedings are contained in the PRO document WO 71/352.

Court Martial Proceedings

The members of the courts martial were Colonel D. Sapte (President), Major W.R. James and Major D.B. Frew.

To the charge of " ... did take part in an armed rebellion and in the waging of war against His Majesty the King, such act being of such a nature as to be calculated to be prejudicial to the Defence of the Realm and being done with the intension and for the purpose of assisting the enemy."

The 1st witness was Major J.A. Armstrong who stated

On 30 April 1916 I was present at Bride Street and Patrick's Park where the British troops were fired upon. The accused was one of a party which surrendered about 5pm. He was dressed in a Volunteer Captain's uniform and was armed. These officers were armed with pistols or revolvers. These men who surrendered came from the direction in which firing had taken place.

Con Colbert did not call any witnesses in his defence but made the following statement:

I have nothing to say.

Court Martial Verdict

Con Colbert was found guilty and sentenced to death by shooting. This sentence was confirmed by General Maxwell. Between 3.45 and 4.05am on 8 May 1916, Con Colbert was shot in the former stonebreakers yard at Kilmainham Prison. His remains were later buried in Arbour Lane Cemetery.