After Robert Head was slain in a knife fight over drugs on the south side of Chicago on April 3, 2002, police found a bloody knife nearby. Police sent the knife to the Illinois State Police crime laboratory, which sent it to a private forensic laboratory, Orchid Cellmark, for DNA analysis. On April 26, three weeks and two days after the crime, Maurice Patterson, 35, was arrested and put into a lineup from which he was identified by three witnesses. Based on those identifications, Patterson was charged with the murder.
On September 18, 2002, Orchid Cellmark notified the State Police Forensic Science Center that the blood on the knife was a mixture of the victim's blood and the blood of an unknown person. The State Police then ran the unknown person's DNA profile through the state Combined DNA Index System (CODIS) and identified him as James Starkey, a drug addict with a record of violence. On February 3, 2003, the State Police sent a report to Dolores Myles, a Chicago police detective assigned to the case, saying that Starkey's blood was on the knife. A copy of the report was sent to Kathleen Van Kampen, an assistant Cook County state's attorney working on the case. The report did not mention that Head's blood had been found on the knife, although it referenced Cellmark's September 18 report, which had said that.
The prosecution of Patterson proceeded before Cook County Circuit Court Judge James B. Linn. At a pretrial hearing on February 26, 2003, Linn asked Van Kampen about the forensic analysis of the knife. She responded that her "best guess" was that the knife was not the murder weapon because the DNA on it came neither from Patterson — true — nor from Head — false. At Patterson's three-day jury trial in November 2003, Detective Myles testified that Head's DNA was not on the knife. Patterson's lawyer, Assistant Public Defender Robert Strunk, did not challenge that incorrect assertion. In closing argument, Assistant State's Attorney David Weiner, Van Kampen's trial partner, told the jury the knife could not have been the murder weapon because Head's DNA was not on it. Based on in-court identifications of the three eyewitnesses, the jury found Patterson guilty.
At his sentencing in February 2004, Patterson professed innocence — "I didn't kill that man. I never saw that man, never in my life" — vowing that he would be back and asking Linn, "[A]re you going to apologize to me?" Linn sentenced him to 30 years in prison. In November 2007, Patterson obtained copies of the forensic reports in the case with the names blacked out. In October 2009, the Cook County State's Attorney's Office informed Patterson's appellate lawyer, Steven Becker, of the Office of the State Appellate Defender, that — contrary to the testimony of Detective Myles and Assistant State's Attorneys Van Kampen and Weiner — Head's DNA had been on the knife along with Starkey's DNA.
The State joined in a motion to vacate Patterson's conviction, which Judge Linn granted on November 23, 2009. The prosecution, however, did not dismiss the charges until October 8, 2010, after Karen Daniel, a staff attorney at the Center on Wrongful Convictions, entered the case and filed a motion on Patterson's behalf asking that the charges be dismissed based on due process violations.
Daniel asked Weiner and Van Kampen to explain why incorrect false information had been provided at Patterson's trial, but they refused to say. Starkey at that point was in prison, scheduled to be released a few days later. Rather than pursuing charges against Starkey, however, State's Attorney Anita Alvarez allowed him to walk free and issued a statement denying that Van Kampen and Weiner had done anything wrong.
— Rob Warden