The New York. U.S., Sing Sing Prison Admission Records, 1865-1929, provides the following information on Michael Ahearn:
* He had been in prison times before, (a) the first at an unknown time, (b) the second time on October 20, 1874, and (c) the third time on August 12, 1878.
* His "right name" was Michael Flanagan.
* He was 26 and listed his occupation as vendor.
* He had a medium complexion, gray eyes and brown hair.
* He was 5'8"-3/4 and 165 pounds.
* He can't read or right.
* He was Catholic and married.
* His mother was Bridget Ahearn.
* He was arrested on or at 93 something and his mother lived on or at 93 something.
https://www.ancestry.com/discoveryui-content/view/67010:8922?tid=&pid=&queryid=4edf5646-ce3d-411e-988e-1b2f754055e6&_phsrc=nxM7040&_phstart=successSource