Herbert Richard Baumeister (April 7, 1947 – July 3, 1996) was an American businessman and suspected serial killer who came under suspicion of murdering over a dozen men in the early-to-mid 1990s, most of whom were last seen at gay bars in central Indiana. Police ultimately found the remains of eleven men, eight identified, on Baumeister's property. He died by suicide after a warrant was issued for his arrest. Since his death, he has come under suspicion for the murders of twelve other men along Interstate 70 in Indiana and Ohio, which occurred from the early 1980s to the early 1990s.

Hadden Irving Clark (born July 31, 1952) is an American murderer and suspected serial killer currently serving two 30-year sentences for the murders of 6-year-old Michele Lee Dorr in 1986, and 23-year-old Laura Houghteling in 1992. He was also given a 10-year sentence for robbery after stealing from a former landlord.

Joseph Edward Duncan III (February 25, 1963 – March 28, 2021) was an American convicted serial killer and child molester who was on death row in federal prison following the 2005 kidnappings and murders of members of the Groene family of Coeur d'Alene, Idaho. He was also serving 11 consecutive sentences of life without parole for the 1997 murder of Anthony Martinez of Beaumont, California. Additionally, Duncan confessed to — but had not been charged with — the 1996 murder of two girls, Sammiejo White and Carmen Cubias, in Seattle, Washington. At the time of the attack on the Groene family, Duncan was on the run from a child molestation charge in Minnesota.