Cook County Sheriff Tom Dart, left, speaks at a news conference in Chicago, Wednesday, July 19, 2017, where he announced the identity of James Byron Haakenson, of Minnesota, as one of the victims of serial killer John Wayne Gacy. The teenager had left his home in 1976 and was last heard from in August of that year when he called his mother and told her he was in Chicago. (AP Photo/G-Jun Yam) Photo: G-Jun Yam, Associated Press
These are America’s most notorious serial killers.Information gathered from www.biography.com, Wikipedia and murderpedia.org. Photo: SpxChrome, Getty Images / (c) spxChrome
Richard RamirezRamirez was convicted in 1989 for 13 counts of murder. His crimes took place in California between 1984 and 1985. He died in 2013 of cancer while on death row. Photo: LENNOX MCLENDON, AP Photo / AP1985
The Boston StranglerThe person or persons responsible for the murders of 13 women in Boston in the early 1960s have never been caught. Though convicted rapist Albert DeSalvo confessed to the crimes, he later recanted. He was found dead in 1973 while serving time in prison. This is a photo of five of eight women whose murders are linked to the Boston Strangler. Left to right are Sophie Clark, 21; Jane Sullivan, 67; Helen E. Blake, 65; Ida Irga, 75; and Patricia Bissette, 23. Photo: AP
John Wayne GacyGacy, the "Killer Clown," was convicted of murdering 33 teenage boys in the 1970s in Chicago. Of these 33 known murders he was sentenced to death for 12 of them. He was executed in 1994. Photo: Tim Boyle, Getty Images / Hulton Archive
David BerkowitzKnown as the "Son of Sam" and ".44 Caliber Killer," Berkowitz was convicted of killing six people and attempting to kill seven more in New York City between 1976 and 1977. He was sentenced to 25 years to life for each murder. Berkowitz continues to serve his sentence in New York. Photo: Hulton Archive, Getty Images / Archive Photos
Dennis RaderThe "BTK Killer" was convicted of 10 murders in Wichita, Kan., in 2005 for killings between 1974 and 1991. The BTK stands for Bind, Torture, Kill. He was sentenced to 10 consecutive life sentences and continues to serve time in a Kansas prison. Photo: Getty Images / 2005 Getty Images
The Hillside StranglerTwo men, Angelo Buono (above right) and Kenneth Bianchi, were convicted of raping, kidnapping and murdering 10 women between 1977 and 1978 in Los Angeles. Both received life sentences. Buono died in prison in 2002 from cardiac arrest, and Bianchi continues to serve his sentence. Photo: Rasmussen, AP Photo / AP1981
Gary RidgwayThe so-called "Green River Killer," Ridgway was sentenced in 2003 to 48 consecutive life terms after confessing that he'd killed a string of women in Washington State in the 1980s and '90s. He would later confess to a total between 65 and 71. He remains in prison in Washington. Photo: ELAINE THOMPSON, AP Photo / AP2003
Jeffrey DahmerCalled the "Milwaukee Cannibal," Dahmer was alleged to have raped and murdered 17 young men between 1978 and 1991. He was convicted of 16 murders in 1992 and given life in prison. He was beaten to death while serving his time in 1994. He was also known to dismember and eat parts of his victims. Photo: ALLAN Y. SCOTT, AP Photo / AP1991
Arthur ShawcrossCalled the "Genesee River Killer," Shawcross was convicted in 1990 of killing 10 people in New York between 1972 and 1989. He was sentenced to 250 years to life in prison. He was convicted of another murder months later and given another life sentence. He died from cardiac arrest in 2008. Photo: AP Photo / AP1990
Aileen WuornosBetween 1993 and 1994 Wuornos was convicted of six of the seven murders she was accused of committing while working as a prostitute between 1989 and 1990. She was given six death sentences and was executed in Florida in 2002. Photo: Getty Images / 2002 Getty Images
Ted BundyThe exact number of victims Bundy killed is unknown. He once confessed to 30 murders, but was connected to 36. The span of killings were between 1974 and 1978. He was given the death penalty in Florida in 1979 for the murder of two college students he raped and murdered. He would receive another death sentence in 1980 for the murder of 12-year-old Kimberly Leach. Bundy was executed in 1989. Photo: Bill Frakes, Getty Images / Bill Frakes
Edmund Emil KemperKemper, also called "The Coed Killer" killed his first victims in 1964 when he was 15, his grandparents. He would serve about five years in a state hospital. Between 1972 and 1973 He murdered six female hitchhikers, his mother and mom's friend. He was convicted of eight murders in 1973 and received a life sentence. He continues to serve his sentence in a California prison. Photo: AP Photo / AP1973
Ronald DominiqueIn 2006 Dominique confessed to murdering 23 men between 1997 and 2006 in Louisiana. He was convicted of rape and murder in 2008 and sentenced to life in prison. He continues to serve his sentence in Louisiana. Photo: ALEX BRANDON, AP Photo / AP
Herman Webster MudgettBetter known by his alias H.H. Holmes, he was convicted of four murders and six attempted murders during the 1893 World's Columbian Exposition in Chicago. However, Holmes had confessed to 27 murders, nine of which authorities verified. His true body count has been noted for being as high as 200. Holmes actually built a hotel, the World's Fair Hotel, later called "Murder Castle," which he designed in part to help him capture, torture and murder his victims, mostly female. Photo: Chicago History Museum, Getty Images / Not to be reproduced or used without written permission from CHM Rights & Reproductions Dept.
New sketches of 2 unidentified victims of 'Killer Clown' Gacy
Authorities have released new sketches of two unidentified young men slain in the 1970s by John Wayne Gacy, one of the most notorious serial killers in American history.
Gacy tortured, raped and murdered young men and boys, and buried many of them in the crawl space of his home in Cook County, Ill. He killed at least 33 people between 1972 and 1978.
Six of his victims have never been identified.
Police are hoping that friends or family members will recognize the victims from the two new, highly detailed facial reconstructions made public Monday. Artists for the National Center for Missing & Exploited Children teamed up with the Cook County Sheriff's Office to create the drawings of "John Doe 10" and "John Doe 13" as they appeared at the time of their murders.
This 1978 file photo shows serial killer John Wayne Gacy.
The John Does could have come from any part of the country, as Gacy preferred to prey on youths who were hitchhikers or bus travelers rather than residents of the Chicago area where he lived. He would often lure his victims by posing as a police officer or offering construction work.
John Doe 10 was a young white male believed to be between 17 and 21 years. He was between 5-foot-7 and 5-foot-11. Investigators said he had previously suffered an injury to his left collarbone that had healed well over time. He also had a few dental fillings.
John Doe 13, was also a white male, 18 to 22. He was approximately 5'9' to 6'2' and had dark brown wavy hair. His friends would have known that one of his upper teeth was displaced behind another tooth.
WGN: Crime scene at John Wayne Gacy's house, Gacy's arrest and trial in 1978 and 1979 in Chicago.
Media: SFGATE
In 2011, one of Gacy's victims, 19-year-old William George Bundy, was identified through DNA testing. Last year, another unidentified victim was found to be James "Jimmie" Haakenson, a 16-year-old from St. Paul, Minn.
Gacy, was known at the "Killer Clown" because he enjoyed dressing up as a "Pogo the Clown" or "Patches the Clown" and entertaining children at hospitals, fund-raising events and other charitable events.