The capital murder trial of Tomasz Kosowski, a 47-year-old Dartmouth Medical School graduate and former plastic surgeon, has drawn intense legal scrutiny in Clearwater, Florida, as he attempts to represent himself without a defense team. Facing the death penalty for the first-degree murder of attorney Steven Cozzi, Kosowski has made several high-stakes decisions, including waiving his right to a jury trial and initiating erratic cross-examinations of state witnesses.
According to court proceedings reported by the New York Post, Kosowski stunned the Pinellas County Justice Center during a session on September 16, 2026. While objecting to the prosecution’s questions regarding trash bags recovered from his vehicle, Kosowski turned to Assistant State Attorney Nathan Vonderheide and asked him to step inside one of the bags to demonstrate its capacity. Judge Joseph Bulone immediately intervened, denying the highly unusual request.
The Decision to Proceed Pro Se
Kosowski’s decision to represent himself—known legally as proceeding pro se—came after multiple defense attorneys and public defenders withdrew from his case. In addition to rejecting professional counsel, Kosowski chose to waive his right to a jury trial. This means Judge Bulone alone will determine his guilt and decide whether he should face the death penalty. Legal experts often warn against pro se representation in capital cases due to the complexity of rules of evidence and the high stakes involved.
Throughout the first several days of the trial, Kosowski remained largely silent during witness testimonies. He declined to cross-examine dozens of witnesses presented by the prosecution, only beginning to ask his first questions on September 17, 2026. This passive approach contrasted sharply with the aggressive, sometimes bizarre statements he made when he did speak.
The Disappearance of Steven Cozzi and the Prosecution’s Case
The state’s case centers on the disappearance of 41-year-old attorney Steven Cozzi, who vanished on March 21, 2023, from his Clearwater law office. Cozzi was representing defendants in a medical billing lawsuit that Kosowski had filed against his former employer. Prosecutors argue that Kosowski, driven by deep resentment over the ongoing litigation, meticulously planned and executed Cozzi in the office’s restroom before disposing of his body.
Despite extensive searches by law enforcement, Cozzi’s body has never been found. However, prosecutors have presented substantial circumstantial and forensic evidence. Investigators discovered Cozzi’s blood on the men’s bathroom floor, on paper towels, and inside the drain of the Blanchard law office. Furthermore, forensic analysts identified a mixture of Kosowski’s DNA and Cozzi’s blood on the exterior of the restroom door.
Surveillance footage from the morning of the disappearance shows an individual entering the law office carrying a large box at approximately 8:30 a.m. Less than two hours later, the same individual is seen wheeling a heavy wagon out of the building and struggling to lift it into a gray Toyota Tundra truck—a vehicle matching Kosowski’s. On the morning of the murder, both Kosowski and Cozzi were scheduled to participate in a 10:30 a.m. telephonic court hearing. Kosowski called in, but Cozzi never did.
When police arrested Kosowski four days later on March 25, 2023, they discovered what prosecutors described as a “murder bag” inside his vehicle. The bag contained a Guy Fawkes mask, ski masks, brass knuckles, a crowbar, a Taser, syringes, and a vial of succinylcholine—a powerful neuromuscular blocker that causes paralysis.
Evidence of Concealment and Next Steps
During the trial, prosecutors also introduced video footage of Kosowski’s arrest. Detective Jerry Hunt of the Largo Police Department testified that after Kosowski was informed that officers had obtained a warrant to swab him for DNA, the defendant immediately began scraping his fingernails against his teeth and sucking on his fingers inside the patrol vehicle. The state argued this was a deliberate attempt to destroy physical evidence before the warrant could be executed.
The trial is expected to conclude in the coming days, with Judge Bulone delivering the final verdict. Because Kosowski has waived a jury, the sole responsibility of weighing the extensive forensic evidence, the circumstantial timeline, and the defendant’s highly unorthodox self-defense rests entirely on the court.