He received a Juris Doctor from Rutgers School of Law–Camden in 1976, where he was an Earl Warren Scholar.

At the recommendation of then Delaware United States Senator Joe Biden, Sleet was nominated by President Bill Clinton on January 27, 1998, to a seat vacated by Joseph J. Longobardi.

[2] In February 2018, Sleet announced his plan to retire from the federal bench in the fall of 2018.

[2] In 1995, Sleet was appointed by then U.S. Attorney General Janet Reno for a 2-year term to the Attorney General's Advisory Committee ("AGAC"), a group designed to set policy and strategy for the United States Department of Justice, and also a group which Sleet was made Vice Chair of in 1995-1995 by Reno in August 1995.

[2] Additionally, Judge Sleet was presented the Distinguished Service Award in 1994 by the National Association for the Advancement of Colored People (NAACP), Central Delaware Branch.