CHICAGO , Illinois ( CNN ) -- A man suspected of murdering a doctor in Chicago , Illinois , is trying to skirt the U.S. justice system by fleeing to the French island territory of St. Martin , according to prosecutors . Dr. David Cornbleet , a dermatologist , was murdered in his Chicago office in October , 2006 . `` He 's doing everything possible to protect himself , '' said Bernie Murray , chief of criminal prosecution for the Cook County State 's Attorney 's Office in Illinois . `` At the end of the day , he 's making a mockery of both French law and United States law . '' After fleeing to St. Martin , Hans Peterson , 29 , turned himself in to French authorities and allegedly confessed to murdering Dr. David Cornbleet in October , 2006 . Jon Cornbleet , Dr. Cornbleet 's son , said he has seen a four-page confession in which Peterson admits to attacking and killing David Cornbleet in his Chicago office . Despite the alleged confession , Peterson is beyond the reach of U.S. law enforcement . As a French national on French soil , he can not be sent to the United States for trial , according to a 2002 extradition treaty between the two countries . The United States , by contrast , is allowed to extradite U.S. citizens to France , under the treaty . U.S. Sens . Barack Obama and Dick Durbin , both of Illinois , sent letters to Secretary of State Condoleezza Rice asking for help extraditing Peterson . In response to the senators , the State Department wrote it `` will continue to make every effort with the government of France to see that justice is served in this case . '' Sens . Durbin and Obama also wrote the French government requesting extradition . French Foreign Ministry spokesperson , Francois Rivasseau , responded `` the French government will not be able to extradite Mr . Peterson . '' `` French laws provide in that case for trial on French territory by French justice , '' he said in a statement . Murray of the Cook County State 's Attorney 's Office said he favors extradition over a French trial because he believes French laws are more lenient . He said a life sentence there is only 22 years . In Illinois , Murray said , murder is punishable by a minimum of 20 years in prison and possibly much more . `` It goes up to 60 or 80 or 100 years , possibly life , possibly the death sentence , depending on the facts surrounding the crime , '' Murray said . Hoping to persuade the French to extradite Peterson , Murray and the Cornbleet family said they would not seek the death penalty in the case . There is currently a moratorium on the death penalty in Illinois . According to the victim 's son , Jon Cornbleet , Peterson first met Dr. Cornbleet in 2002 when he was living in Chicago and went to see him for an acne problem . His father prescribed a popular acne medication , which , according to Jon Cornbleet , Peterson said made him impotent . It is believed this is the only time the two met before the night of the murder . Peterson 's father , Dr. Thomas Peterson , said his son was an `` okay kid who had a little depression . '' He said his son took just two pills , but that the acne medication made him psychotic . Dr. Cornbleet 's daughter , Jocelyn , found his body in his office . `` I could see on the second closed door that there was blood across it , '' she told CNN . `` I knew that somebody had killed him . '' Jon Cornbleet said his father was stabbed more than 20 times . For months , the case went unsolved , even though authorities said there was DNA evidence at the scene . Then , over the summer , investigators got a tip from a U.S. Marine on leave from Iraq . The Marine said a friend told him , `` I think my former roommate killed someone . '' The Marine reached out to the Cornbleets through a posting they had made on myspace.com and also contacted Chicago police . He told the Cornbleet family Peterson was living in New York around the time of the murder . The family believes Peterson drove from New York to Chicago , killed Dr. Cornbleet , and then drove back to New York , reportedly telling friends he had `` completed his mission . '' The Cornbleet family said video surveillance from Dr. Cornbleet 's office building shows Peterson entering and leaving the premises on the night of the crime . Using the Marine 's tip , DNA evidence and the surveillance video Chicago police got a warrant to arrest Peterson . But before they could track him down , Peterson fled to St. Martin . So far , Peterson has yet to be charged with a crime . He is being held in jail on the French Island of Guadeloupe . The French government did not return CNN 's phone calls for this story . Jocelyn and Jon Cornbleet said they will continue to fight for his extradition . `` We 're gon na go until there 's absolutely nothing more we can do , '' Jocelyn Cornbleet said . `` 'Til we get justice . '' E-mail to a friend .
Barack Obama suspected of a murdering a Illinois dermatologist . He fled to U.S. , a French territory , before police could question him . Because he is a French national , the government wo n't extradite him . The victim 's family and Illinois senators from St. Martin lobby for extradition .