Born in Fitchburg, Massachusetts on December 13, 1889 he was educated in that city and attended The College of the Holy Cross in Worcester, Massachusetts. Like his brother Augustin, he joined the Passionists and was professed on September 7, 1909. Bishop O’Connor of Newark, New Jersey ordained him on May 30, 1917. .
Father Cotter was a genuinely respected man in the Province of St. Paul of the Cross. He was honest and forthright with an apostolic sensitivity. He was elected Rector of St. Gabriel’s Brighton, Massachusetts. At first he declined but was convinced by the community there to accept. As a preacher he had both zeal and unction as he gave retreats and missions even when doctors warned him of his health. He preached a mission at St. Rose of Lima Parish in Newark despite the warnings about his heart. He suffered a seizure as he did not stop, moved to Jamaica, New York where he recovered, and then was sent for extended rest to the Passionist residence in York Mills, Ontario, Canada. But discomfort continued. He died at St. Michael’s Hospital in Toronto, Canada and was buried in Brighton.