He was implicated, if not as the organiser, then at least as the spirit behind the assassinations of Lord Frederick Cavendish and Under Secretary Thomas Henry Burke in the Phoenix Park murders of 6 May 1882.

Although he was an ardent supporter of the goals of both Irish home rule and the abolishment of landlordism in Ireland, he became much more of a revolutionist and opposed to Parnell's methods of negotiation.

[6] These knives, it was stated, had been lying for some time in the London offices of the Irish National League of Great Britain.

[7]: 553  He had served in an Irish company attached to one of the French regiments in the army under Bourbaki during the Franco-Prussian War and had received several medals for meritorious conduct.

I do not say you should alone use dynamite, or the knife, or the rifle, or parliamentary agitation, but I hold no Irishman true who will not use all and each method as the opportunity presents itself.