[5] Sampson worked for the Department of Environmental Conservation and as a Staff Attorney to the Legal Aid Society of New York.
[9] In 2005, Sampson made an unsuccessful bid to become District Attorney of Kings County, New York, opposing the incumbent, Charles "Joe" Hynes.
[14] On the same day, Sampson was stripped of his committee assignments and ranking positions and removed from the Senate Democratic Conference.
[18][19] On March 10, 2016, the Appellate Division of the New York Supreme Court suspended Sampson from the practice of law.
[20] Sampson filed an appeal based on a 2016 United States Supreme Court decision that overturned the conviction of former Virginia Governor Bob McDonnell.