Wikipedia has a fascinating entry about the real-life events upon which the film is based. By the way, I've heard the Dragnet episode referenced in this article, and it's great stuff -- it's widely available on various Old Time Radio sites.
THE WINEVILLE CHICKEN COOP MURDERS
The Wineville Chicken Coop Murders (also known as the Wineville Chicken Murders) were a series of kidnapping and murders of young boys occurring in Los Angeles and Riverside County, California from 1928 through 1930. The case received nationwide attention, and events related to it exposed corruption in the Los Angeles Police Department. The 2008 film Changeling is based upon events related to this case.
In September 1928, the Los Angeles Police Department visited the Northcott Ranch in Wineville, Riverside County. In 1926, Sanford Clark, the then-14-year-old nephew of ranch owner Gordon Stewart Northcott, had been taken by Northcott from his home in Saskatchewan, Canada. Clark was beaten and sexually abused by Northcott, before a family member informed police of the situation. Police found Clark at the ranch and took him into custody. Clark claimed that Northcott had kidnapped, molested and killed several young boys, with the help of Northcott's apparent mother, Sarah Louise Northcott, and the forced participation of Clark himself. The police found no complete bodies at the site, but discovered body parts, the personal effects of missing children, and blood-stained axes. Clark said quicklime was used to dispose of the remains and the bones had been dumped in the desert. The Northcotts had fled to Canada, but they were arrested near Vernon, British Columbia.
CASE AND TRIALl
Sarah Louise Northcott initially confessed to the murders, including that of 9-year-old Walter Collins. She later retracted her statement, as did Gordon Northcott, who had confessed to killing five boys. On February 8, 1929, after a 27-day trial in Riverside County, California before Judge George R. Freeman, Gordon Northcott was convicted of the murders of brothers Lewis and Nelson Winslow (12 and 10, respectively), who went missing from Pomona on May 16, 1928, and an unidentified Mexican boy, though it was believed the killings could have numbered as many as 20. The jury heard that he kidnapped, molested, tortured, killed, and dismembered these and other boys throughout 1928. On February 13, 1929, Judge Freeman sentenced Northcott to be hanged. The sentence was carried out on October 2, 1930. Sarah Louise Northcott was convicted of Walter Collins' murder. She was sentenced to life and served her sentence at Tehachapi State Prison. She was paroled after serving less than 12 years of her sentence. During the trial Gordon Northcott learned that Sarah Louise, who he had thought was his mother, was actually his grandmother. Sarah Louise stated that Gordon was the result of incest committed by her husband, Cyruss George Northcott, against their daughter Winifred.
Walter Collins (9) went missing from Los Angeles on March 10, 1928, after having been given money by his mother to go to the cinema. His disappearance received nationwide attention, and the Los Angeles Police Department followed up on hundreds of leads without success. The police faced negative publicity and increasing public pressure to solve the case, until five months after Walter's disappearance, when a boy claiming to be Walter was found in DeKalb, Illinois. Letters and photographs were exchanged, before Collins paid for the boy to be brought to Los Angeles. A public reunion was organized by police, who hoped the successful resolution would counteract the negative publicity they had received for their inability to solve this case and others. They also hoped the uplifting human interest story would deflect attention from a series of corruption scandals that had sullied the department's reputation. At the reunion, Collins claimed that the boy was not Walter. She was told by the officer in charge of the case, police Captain J.J Jones, to take the boy home to "try him out for a couple of weeks," and Collins agreed.
Three weeks later, Collins returned to see Captain Jones and persisted in her claim that the boy was not Walter. Even though she was armed with dental records proving her case, Jones had Collins committed to the psychopathic ward at Los Angeles County Hospital under a "Code 12" internment—a term used to jail or commit someone who was deemed difficult or an inconvenience. During Collins' incarceration, Jones questioned the boy, who admitted to being 12-year-old Arthur Hutchins Jr., a runaway from Illinois but who was originally from Iowa. A drifter at a roadside café in Illinois had told Hutchins of his resemblance to the missing Walter, so Hutchins came up with the plan to impersonate him. His motive was to get to Hollywood so he could meet his favorite actor, Tom Mix. Collins was released ten days after Hutchins admitted that he was not her son, and filed a lawsuit against the Los Angeles Police Department. This aspect of the case is depicted in the 2008 film Changeling.
Collins went on to win her lawsuit and was awarded $10,800, which Jones never paid. Five years after Northcott's execution, one of the boys that Northcott allegedly killed was found alive and well. As Walter Collins' body had not been found, Christine Collins still hoped that Walter had survived. She continued to search for him all her life, but unsuccessfully, until she faded into obscurity without ever knowing her son's fate. The last public record of Christine Collins is from 1941, when she attempted to collect a $15,562 judgment against Captain Jones, by then a retired police officer, in Superior Court.
ARTHUR HUTCHINS, JR.
Arthur J. Hutchins, Jr. wrote in 1933 how and why he fooled the police, the real missing Walter's closest friends, and even Walter’s dog and cat in 1928. Hutchins biological mother died when he was 9. He pretended to be Walter Collins to get as far away as possible from his stepmother, Violet. Hutchins had been living on the road for a month when DeKalb, Illinois, police brought him in and began asking him questions about Walter Collins. Originally, he stated that he did not know about Walter, but changed his story when he saw this as a means to get to California.
After Hutchins confessed to the hoax, he was placed for two years in the Iowa State Training School for Boys in Eldora, Iowa. Eventually, he expressed remorse for what he had done to Christine Collins and wrote, "I know I owe an apology to Mrs. Collins and to the state of California."
After Arthur Hutchins became an adult, he sold concessions at carnivals and eventually made it back to California as a horse trainer and jockey. He died of a blood clot in 1954, leaving behind a wife and young daughter, Carol. According to Carol Hutchins, "My dad was full of adventure. In my mind, he could do no wrong."
Investigators found an axe and bones, hair and fingers from three of the victims buried in lime near the chicken house at the Northcott ranch near Wineville, hence the name "Wineville Chicken Coop Murders." Wineville changed its name to “Mira Loma” on November 1, 1930, due in large part to the negative publicity surrounding this case. Wineville Avenue, Wineville Road, Wineville Park and other geographic references provide reminders of the community's former name. Someone currently lives in the home where Gordon Stewart Northcott and Sanford Clark lived. The lot was subdivided, the chicken coops were removed, and a home was built on the site.
"The Big Imposter," an episode of the radio series Dragnet, which aired on June 7, 1951, was based on this case. When the show moved to television, the radio script was adapted into a teleplay and broadcast on December 4, 1952. The plot of the episode focuses primarily on the story of Arthur Hutchins' impersonation of Walter Collins. Oddly, in this version, the parental figure who reports the disappearance of the character based on Walter Collins is a widowed grandfather, raising the child on his own after the deaths of the boy's parents, rather than a single mother.
Changeling, a 2008 film directed by Clint Eastwood, is also based on the Northcott case. The film primarily depicts the plight of Christine Collins, the mother of Walter Collins, and her search for her real son.
"Y'know, that's one of the things I like about Mitt Romney. He's been consistent since he changed his mind." -- Christine O'Donnell