In one he had been sitting as a judge at Canterbury Crown Court, in another he was a barrister.
Mr Dunn-Shaw also used social media accounts to post critical comments.
A spokesman for the Judicial Conduct Investigations Office said: "In his own name he used publicly available social media sites to post material or not remove material which was not compatible with the dignity of judicial office or suggested a lack of impartiality on matters of public controversy.
"The Lord Chancellor and the Lord Chief Justice concluded that this behaviour fell below the standard expected of a judicial office holder and have removed Mr Dunn-Shaw from judicial office."
Mr Dunn-Shaw, who has experience both in prosecution and defence, has worked on more than 45 murder trials during his career as well as death by dangerous driving, drugs smuggling, sexual offences and fraud.