[1] Born in Dublin, Ireland to James and Rose Byrnes, he immigrated to New York City as a child.

[7] In 1891, three years after publicly criticizing London police officials on the way they handled the Jack the Ripper investigations, Byrnes was faced with a similar crime in New York.

Amid mammoth publicity, Byrnes accused an Algerian, Ameer Ben Ali (nicknamed Frenchy) of the crime.

[8] Byrnes also successfully obtained a confession from gang leader Mike McGloin, who was convicted and executed for the murder of a tavern-owner during a robbery.

The television documentary Secrets of New York episode of October 22, 2013, credited Byrnes as "a man who invented America's modern detective bureau.

[1] His funeral was at the Church of the Blessed Sacrament at Broadway and Seventy-first Street in Manhattan, New York City.