Gacy:
http://en.wikipedia.org/wiki/John_Wayne_Gacy
Excerpt:
'He was convicted and later executed for the rape and murder of 33 boys and young men between 1972 and his arrest in 1978, 27 of whom he buried in a crawl space under the floor of his house, while others were found in nearby rivers. He became notorious as the "Killer Clown" because of the many block parties he threw for his friends and neighbors, entertaining children in a clown suit and makeup, under the name of "Pogo the Clown." He was also in the Guinness Book of World Records for the longest sentence imposed on a mass murderer; he was given 21 consecutive life sentences and 12 death sentences.'
