Missouri Lawyers Awards 2025: Sean O’Brien

Distinguished Teaching Professor, UMKC
Kansas City

When Sean O’Brien’s work helped free Sandra Hemme from prison for a murder she confessed to but never committed, he found himself staggered by just how much of her life she’d lost to incarceration.

“I was sworn in as a lawyer two months before she went to prison,” mused O’Brien who is now 68 years old.

In fact, Hemme is thought to be the longest-serving exonerated woman in America, spending more than four decades behind bars before work by O’Brien and others pieced together the evidence needed to free her. It is one of 17 exonerations he’s been a part of, either as counsel or record, expert or consultant.

“I think it is a cautionary tale about false confessions and interrogation methods,” he said, noting the numerous rounds of questioning Hemme endured. “I teach my students at the law school that interrogation is not investigation. It is really a strategy to mousetrap a person into saying something incriminating.”

O’Brien was able to gather substantial evidence pointing to another suspect in the case. In some instances, police were helpful and were as convinced of Hemme’s innocence as O’Brien was. He recalled one interview with a cop who felt her conviction was in error.

“He started crying and said ‘I’ve been waiting for you’,” O’Brien said.

O’Brien has also helped to make law. His work before the U.S. Supreme Court in Schlup v. Delo helped set the standard for innocence claims in federal court while Stewart v. Martinez-Villareal empowered habeas courts to prevent the execution of insane prisoners.

O’Brien, a former public defender in Jackson County, has served as chair of the state bar’s Criminal Law Committee and President of the Missouri Association of Criminal Defense Lawyers.

Working to gain exonerations since the 1990s, the 68-year-old has earned the Spurgeon Smithson Award for improving access to justice and the Jackson County Legal Leaders Award. Recipient of a Humane Letters degree from Benedictine College, he received recognition from UMKC as it’s Alumnus of the Year in 2023. He has also previously been named Missouri Lawyers Weekly’s Lawyer of the Year and is a recipient of the KCMBA’s Lifetime Achievement Award.