The Nobel Committee has an interesting database of all the nominees for the Nobel Peace Prize from 1901 to 1951. Nominations are kept secret for 50 years. Nominees who, like unrepentant multiple murderer Stanley Williams, do not appear to have deserved the nomination include:

Mussolini (1935, by a French law professor, and by the law faculty at a German university);
Stalin (1948, by a Czech professor)(also, 1945 by a former Norweign foreign minister, although the minister only wrote that Stalin was qualified for the prize, and did not formally nominate him);
Kaiser Wilhelm II (1911, by the President of UC Berkeley; 1917, by a German professor and by a Turkish law faculty);
Hitler (1939, by a member of the Swedish parliament, although the nomination was withdrawn before the Committee considered it);
Alfred Ploetz (the founder of racial hygiene in Germany; 1936 by a Norwegian parliamentarian, for warning that war would harm biological reproduction);
Neville Chamberlin (somewhat plausibly in 1926 for his role in the Locarno Pact; less so in 1939, with 9 nominations for his role in the Munich Agreement).