The 6-year-old girl vanished from in front of her Joliet Township home during the early evening hours of July 21, 1981.
Since Sarah's disappearance, misinformation and urban legends have been retold as fact and evidence, according to a release from the Will County Sheriff's Office.
When leads in cold cases diminish, it's common to completely review the case from the beginning, according to the sheriff's office.
After a fresh series of interviewers investigators have named William Redden as a person of interest in the case.
Redden has since died, but police said they are are still looking to see if anyone has any information linking Redden to Avon.
In May 2019, a search was made of Redden's former Joliet home. Investigators excavated the crawl space, but no remains were discovered, police said.
The Avon family and the sheriff's office have maintained communication throughout the years. Details and activity provided to the public are kept to a minimum in order to maintain the case integrity, police said.
If anyone has information about the case or Redden, contact the Will County Sheriff's Office Detectives Unit at 815-727-8574. You can also leave anonymous tips on the Will County Sheriff's website at www.willcosheriff.org/enforcement/submit-a-crime-tip. You can also contact Will County Crime Stoppers by telephone at 800-323-6734, or by computer at www.crimestoppersofwillcounty.org/submit-a-tip/.