Mike Snow was a Sergeant of the True Sons. After disagreeing with the True Sons intentions to endanger civilians lives, he defected from them and opened the Castle as a settlement to the refugees from all over the city. After True Sons members approached him and made an offer not to attack them in exchange for tax, he refused. The True Sons then launched rapid attacks against the Castle.
In the latest attempt, they used the chemical DC-62 and fired them into the Castle using mortars from Jefferson Square, which leads to the downfall of the Castle. It is unknown the current status of Mike Snow, but he was most likely killed by the True Sons during the infiltration attempts or the final destruction of the Castle.