I'm a sucker for stories about Big Law partners working pro bono to prove that convicted murderers are actually innocent.

But I'm not so sure that's what this case is about—there are plenty of reasons to be suspicious of Shadwick King, whose beautiful younger wife Kathleen was found dead on a railroad track in Geneva, Illinois in 2014. 

Did she die of a sudden cardiac arrhythmia when she was out on an early morning jog? Or was the crime scene staged by her husband, who strangled her to death in a jealous rage over her involvement with another man?

The all-important question—was her death from natural causes or was it a homicide?—turned on expert testimony. And that's where Winston & Strawn partner Matthew Carter comes in.

Working pro bono, Carter represented King before the Illinois Supreme Court, which on Jan. 24 ordered a new trial for the defendant in a decision with implications for the use of expert witnesses in both criminal and civil cases. 

"[W]e will not condone the calling of experts solely for the purpose of shoring up one party's theory of the case," the state high court wrote in ruling that the testimony of ex-FBI profiler Mark Safarik was improperly admitted.

"[The state was effectively calling a thirteenth juror to the stand to lend his expert imprimatur to the state's characterization of the evidence," the unanimous court continued. "That is a wholly improper use of expert testimony, and we want to make absolutely clear that such testimony is not to be permitted going forward."

On the July evening before 32-year-old Kathleen King died, she and her husband, who is now 52, went to a barbeque at her father's house, where they left their three sons for a sleepover. The couple then went out to a bar until 2 a.m.

Their marriage had been under stress, with talk of divorce. Kathleen had joined the Army Reserves and met a man 10 years her junior during training in Texas. According to the Chicago Tribune, the pair had sent 3,499 text messages to each other in just over two weeks.

Once Kathleen and her husband got home from the bar, King at 4 a.m. sent the man text messages from Kathleen's phone purporting to be from Kathleen, the high court decision states. The messages said she and her husband were presently having sex. At 4:45 a.m., King drove to an ATM and took out $500, which he told police was for car repairs.

Um, okay.

After he got back from the bank, he said Kathleen decided to go out for an early run. At that point, King said he went back to sleep for 30 minutes, then left the house to get gas, "drive round," get donuts and pick up his sons from his father-in-law's house around 10:15. 

His father-in-law testified that this was odd because King "never" picked up the boys. When King arrived, his father-in-law had already been informed that Kathleen was dead. He told King the news, testifying that his son-in-law's immediate response was, "I didn't do anything. I didn't do anything."

 According to his father-in-law, the entire time King was at his house that morning, he never even asked what happened to his wife.

Like I said, there are reasons to be suspicious. 

Moreover, Kathleen usually ran in the park but her body was found on railroad tracks about 1,200 feet from her home. She wasn't wearing her contact lenses or glasses; her earbuds, or her iPhone armband—all of which she normally wore when running. She had on an underwire bra, not a sports bra. One of her socks was on upside down, with the heel on the top of her foot. Her shoes weren't muddy, even though it had rained overnight.

The prosecution's theory was the crime scene was staged—that Kathleen had been killed elsewhere, dressed in running gear and placed on the tracks. However, there was no DNA evidence and no eyewitness.

King was charged with first degree murder.

At trial, the state called the forensic pathologist who performed Kathleen's autopsy. The doctor testified that the cause of death was manual strangulation. 

The public defender, on the other hand, called a forensic pathologist who testified that Kathleen died of a cardiac event brought on by stress, alcohol intoxication, lack of sleep and caffeine consumption. The theory was that she felt poorly while running, sat down on the railroad tracks and then died.

The controversy begins with the third expert, Mark Safarik, who testified for the state.

 Safarik spent 23 years working for the FBI, including as a criminal profiler. According to his website, he "has appeared on Dateline, Court TV, Forensic Files, MSNBC and The Discovery Channel to discuss his cases and analyses. His television series, Killer Instinct, is currently airing on the Biography Channel. Since 2008 he has been a consultant for the popular television series CSI: Las Vegas and Bone."

In an amicus brief, the Exoneration Project and the Innocence Project took issue with the entire concept of criminal profiling.

"A survey of all scientific research on profiling from 1976 to 2016 found no reason to believe that profilers are any 'better than bartenders' at predicting the traits and features of offenders," wrote the Exoneration Project's Karl Leonard and Lindsay Hagy, who also highlighted multiple instances where criminal profilers were dead wrong. (FBI profilers, for example, concluded that the Unabomber was uneducated, when in fact he had a Ph.D. in mathematics.)

The problem here wasn't just that Safarik testified about crime scene analysis. It's that he also weighed in on issues outside his supposed expertise. 

Kane County Judge James Hallock overruled objections from the defense and allowed Safarik to opine on "the cause and manner of Kathleen's death, whether the lividity on Kathleen's body was consistent with her positioning on the railroad tracks, whether certain injuries and abrasions found on Kathleen's body were sustained before or after her death, whether Kathleen's injuries were consistent with her having fallen on the tracks, and whether leaves found on Kathleen's body were consistent with leaves found in and around the Kings' home," according to the Illinois Supreme Court.

The state high court continued, "Safarik is undoubtedly an expert in criminal investigation and crime scene analysis. But that is hardly the same thing as being an expert in forensic pathology or botany, both of which are scientific fields into which Safarik's testimony repeatedly transgressed."

If that wasn't bad enough, Safarik also testified about matters where no experts were needed. As the court put it, this testimony fell "well within the ken of an average juror and therefore did not necessitate expert assistance."

Jurors didn't need an expert to tell them that Kathleen was not likely to have left her contacts, earbuds, and armband at home when she went running, or that she would have picked a sports bra, not an underwire.

Even Safarik's actual expertise—testimony about whether the crime scene was staged or whether the murder was sexually motivated, for example—wasn't useful, the court ruled. Instead, this amounted to "simply testifying about logical conclusions the ordinary juror could draw from human behavior," the Illinois court held, quoting a New Jersey decision that also deemed Safarik's testimony entirely inadmissible.

Allowing Safarik to testify was not a harmless error, the court held. He "broke the tie' between two qualified medical experts who strongly disagreed not only on the cause of Kathleen's death but also on whether that death was even a homicide."

Still, while the Illinois Supreme Court reversed and remanded King's conviction, the judges didn't seem persuaded that he is actually innocent. 

"[W]e have no problem concluding that a rational trier of fact easily could have concluded beyond a reasonable doubt that Kathleen's death was produced by a criminal agency and that defendant is the person responsible."