Desperate to do their part, the Cornbleet family created a profile about the murder on MySpace.com, a popular social networking Web site. In addition to information on the crime, the Web site also included an enhanced copy of the surveillance video from David's office building in hopes that someone might shed some light on the identity of the attacker. The family offered a $25,000 reward for information leading to the arrest and conviction of the murderer.
In April 2007, Cornbleet's family received a tip through MySpace from someone who identified the killer as a man named Hans Peterson. The Chicago police investigated the tip and determined that Peterson was a former patient of David's. In June 2007, upon securing a search warrant for an apartment Peterson had rented in New York, investigators were able to use DNA evidence to connect him to the crime scene. Unfortunately, arresting Peterson would prove far more difficult.
Investigators soon learned that Peterson had left the U.S. for St. Martin Island shortly after the murder. Based on his mother's French heritage, he had applied for and was granted French citizenship. After the arrest warrant was issued, Chicago police filed paperwork for an international warrant. When Peterson learned of the warrant, he confessed to French authorities. The confession included a four-page document detailing the crime.
Peterson claimed that he went to Cornbleet's office that fateful day in October 2006 because of an incident that had occurred four-and-a-half years earlier, when Dr. Cornbleet had prescribed Accutane, a controversial acne medication. Peterson said he suffered massive side effects that did not go away and, as a result, he became impotent. His confession stated that he had gone to the office with the intention of cutting off the doctor's hands and feet, and then cauterizing the wounds with a blowtorch, but he had to stab the doctor to death when David fought back.
Peterson made the confession to French authorities to bypass the U.S. justice system. French law prohibits the death penalty and extradition of any criminal who might be tried under penalty of death.
The Cornbleet family, Chicago police and the U.S. government all appealed to French officials in hopes of persuading them to extradite this murderer. Unfortunately, French officials refused to be swayed and announced that they would be handling the investigation.
In January 2008, French authorities came to the U.S. on a fact-finding mission to learn what they could about the case. Currently, Peterson is being held in a Guadeloupe jail, where French authorities say he will remain until he stands trial. If convicted in France, Peterson will face a maximum sentence of life; however, he will become eligible for parole after serving only 22 years.
