In October of 2017, the Ohio Supreme Court overturned the conviction and death sentence of Joseph L. Thomas. Thomas had been convicted of the murder of Annie McSween, who was killed in November of 2010. The issue that captured the court’s attention—the State’s introduction of irrelevant and prejudicial evidence—was nothing extraordinary as far as criminal appeals go, but the opinion raises critical questions that should be asked far more often.

Mr. Thomas’s appeal centered on the prosecution’s use of “other weapons evidence” against him. This evidence played a key role at trial because it turned out that the State did not have much evidence at all to implicate him in McSween’s terrible death. It had no eyewitness testimony, no DNA or other forensic evidence, no motive, and a defendant without a significant criminal history. However, investigators did locate five knives that Mr. Thomas owned. At trial, prosecutors introduced these knives although, as the Ohio Supreme Court put it, “the state knew [they] were not used in connection with McSween’s murder.”

The Ohio Supreme Court reversed Mr. Thomas’s conviction because “[w]hen the other weapons evidence ‘leads only to inferences about matters that were not properly provable in this case, i.e., the defendant’s dangerous character,’ admission of that evidence prejudices the accused and is reversible error.” Not only did the State rely on the five wholly irrelevant knives, the prosecutor:

further inflamed the jury by presenting and describing these five knives as ‘full Rambo combat knives’ in a case involving a brutal physical assault resulting in strangulation, a broken upper jaw and dentures, multiple rapes, severe stab wounds, and a severe carotid artery and jugular vein resulting in death, especially when none of these knives had anything to do with McSween’s murder. It is apparent that the state offered this evidence to portray Thomas as a person of violent character who acted in conformity with his propensity to kill—a use of evidence prohibited by Evid.R. 404(B) and R.C. 2945.59.

While there is no doubt that the prosecutor’s argument sought to capitalize on negative inferences about Mr. Thomas’s knife collection, the question of the admissibility of these knives fell on the trial court judge. Here, that judge was Richard L. Collins, Jr., in Lake County, Ohio. Judge Collins is slated to preside over Mr. Thomas’s re-trial in August this year. Our criminal justice system entrusts evidentiary rulings to trial court judges as a matter of course. But, in cases like this—where the State wants desperately to rely on evidence that is unrelated to the crime itself—it is worth taking a deeper look at who permitted the State to step out of bounds. Far too often, we find that criminal court judges have extensive experience lawyering only on one side: the prosecution’s. Judge Collins’s biography reveals that he worked as a prosecutor and special prosecutor for decades.

While the judge’s experience as a long-time prosecutor alone does not necessarily make him biased, it raises many questions. Do judges who formerly served as prosecutors tend to favor the State? Do they admit more inculpatory evidence? Do they exclude more exculpatory evidence? (Here, the judge prohibited the defense from introducing favorable polygraph test results suggesting that Mr. Thomas had been honest with investigators when he denied involvement in the crime.) Are they able to accurately assess the potential for evidentiary prejudice against a defendant? And, more broadly, does our system, which places far more prosecutors on the bench, methodically disadvantage defendants for unfair reasons? The Ohio Supreme Court did the right thing in Mr. Thomas’s case, but his case is an exception rather than the rule. When exceptions arise, we need to analyze them, not just for what they stand for explicitly, but what they reveal implicitly about our broken and imbalanced system. Holding prosecutors to account for how they do their jobs is vital; beyond that, in part because so many of these prosecutors become judges, the judiciary also must be held to account.