John Allen
  Served as sheriff starting in 1672, was reappointed sheriff September 8, 1674, serving in that office until several years afterwards. -- Maryland archives: Volume 60, Proceedings of the County Court of Charles County, 1666 - 1674

[ not sure is this the same John Allen? Later notes in Vol 60 describe him as, "...Jno Allen of London Mercht" (p. 504). This shows that the sheriff was a very recent arrival in the Province. ]