Tomasz Kosowski Found Guilty in the Disappearance and Death of Steven Cozzi

The murder case involving former Florida plastic surgeon Tomasz Kosowski reached a major turning point on September 23, 2026, when Pinellas County Judge Joseph Bulone found him guilty of first-degree murder in the death of attorney Steven Cozzi. The verdict came after a bench trial in which Kosowski represented himself and waived his right to have a jury decide his fate.

The case has attracted significant attention because Cozzi disappeared from his Largo law office in March 2023, yet investigators have never recovered his body. Prosecutors argued that the evidence presented during the trial established that Cozzi was killed inside the law office and that Kosowski was responsible. Kosowski denied the prosecution’s account and argued during his closing statement that the state’s theory did not make physical or chronological sense.

The guilty verdict now moves the case into its sentencing phase. Prosecutors are seeking the death penalty, while Kosowski faces either life in prison without parole or a death sentence under Florida law. Further proceedings are scheduled as the judge considers the evidence relevant to sentencing.

Tomasz Kosowski Found Guilty in Cozzi Case

The verdict followed more than a week of testimony and evidence presented in a Pinellas County courtroom. Because Kosowski waived his right to a jury trial, Judge Joseph Bulone alone determined whether the prosecution had proved the first-degree murder charge.

On September 23, the judge ruled that Kosowski was guilty.

The case began more than three years earlier, when Cozzi disappeared from the Blanchard Law office in Largo, Florida. According to trial testimony, Cozzi left behind personal belongings including his phone, keys and wallet. His disappearance prompted an investigation that quickly focused on what had happened inside the law office.

Investigators discovered blood in the office bathroom. Prosecutors later presented DNA evidence indicating that the blood belonged to Cozzi. Other evidence presented at trial was used to establish a connection between Kosowski, the law office and the events surrounding Cozzi’s disappearance.

The prosecution’s case did not depend on the recovery of Cozzi’s body. Investigators searched a Collier County landfill after tracking evidence they believed indicated where the remains had been taken, but the search did not recover Cozzi’s body.

That missing body became one of the central features of the case.

Despite the absence of remains, prosecutors presented a combination of forensic, surveillance and digital evidence. According to testimony reported during the trial, surveillance footage showed a person moving a heavy wagon from the law office toward a Toyota Tundra. Investigators subsequently connected the vehicle to Kosowski.

The prosecution also presented evidence concerning the relationship between Kosowski and Cozzi before the disappearance.

Cozzi had been representing defendants in a civil dispute involving Kosowski. Prosecutors argued that the legal conflict provided a motive for the killing. They also presented testimony concerning earlier confrontations between the two men.

Kosowski, however, disputed the state’s interpretation of the evidence.

What Happened to Steven Cozzi in March 2023?

Steven Cozzi disappeared on March 21, 2023, from the law office where he worked in Largo.

According to testimony reported during the trial, his coworkers became concerned when he failed to return after going to the office bathroom. His belongings remained at his desk, including items that would normally have been taken with him if he had voluntarily left the office.

Investigators eventually found evidence indicating that a violent incident had occurred in the bathroom.

Prosecutors said Kosowski entered the law office, attacked Cozzi and transported him out of the building using a wagon. Surveillance footage became an important part of the state’s presentation because investigators said it showed a person moving a wagon from the building and loading it into a truck.

According to prosecutors, the vehicle was later associated with Kosowski’s home.

The state also presented evidence involving DNA, cellphone data and other forensic findings. Prosecutors argued that the combined evidence established a timeline connecting Kosowski to Cozzi’s disappearance.

One of the most difficult questions for investigators was what happened to Cozzi’s body after he was allegedly removed from the law office.

Authorities eventually searched a landfill in Collier County after investigators developed a theory about where the remains had been discarded. The search lasted several days, but Cozzi was never recovered.

The absence of a body did not prevent prosecutors from pursuing a first-degree murder charge.

The case therefore became an example of how prosecutors can rely on circumstantial, forensic and digital evidence in a homicide prosecution when remains are not recovered.

Kosowski Chose to Represent Himself at Trial

Another unusual aspect of the case was Kosowski’s decision to serve as his own attorney.

Before the trial began, Kosowski waived his right to a jury trial. That meant Judge Joseph Bulone, rather than a panel of jurors, would determine whether he was guilty.

Kosowski also waived his right to counsel and represented himself during the proceedings. The trial began September 14, 2026, more than three years after Cozzi disappeared.

During portions of the trial, Kosowski questioned witnesses and challenged the prosecution’s evidence.

Among the issues he raised were the physical feasibility of the state’s timeline, the DNA evidence, cellphone information and the way prosecutors said Cozzi’s body had been transported.

In his closing argument on September 23, Kosowski continued to dispute the prosecution’s reconstruction of events. He argued that the alleged sequence of events was physically and chronologically impossible.

The judge ultimately rejected the defense position and found Kosowski guilty.

His decision to represent himself will also continue into the sentencing process. According to reports from the courtroom, Kosowski again chose to waive counsel and a jury for the penalty phase.

The court has nevertheless taken steps concerning his legal representation during the penalty proceedings, particularly because prosecutors are seeking the death penalty.

Death Penalty Proceedings Now Move Forward

The guilty verdict is not the final stage of the case.

Kosowski now faces two possible sentences: life imprisonment without the possibility of parole or the death penalty. Prosecutors are seeking the death penalty.

Following the guilty verdict, the court began considering aggravating factors relevant to the potential death sentence.

According to reporting from WTSP, the judge found two of three alleged aggravating circumstances proven, while a third was not established because there was no body, confession or proof showing exactly how Steven Cozzi died. A further Spencer hearing is scheduled for October 8, 2026.

A Spencer hearing gives the court an opportunity to hear additional information before determining the sentence in a death-penalty case.

That means the October proceeding could become another significant moment in the case.

The judge will ultimately determine whether Kosowski receives a life sentence or the death penalty. The penalty phase is separate from the question of guilt, which has already been decided.

For Cozzi’s family, the guilty verdict provides a judicial conclusion on the central question of responsibility, but it does not resolve every unanswered question surrounding the case. Cozzi’s remains have still not been recovered.

The Pinellas County court’s public case records show that the murder proceedings continued through September 2026, including orders and trial events immediately before the September 23 verdict.

The case is therefore still developing.

For now, the key facts are clear: Tomasz Kosowski has been found guilty of first-degree murder in Steven Cozzi’s death, the victim’s remains have never been recovered, and the court must now determine the appropriate sentence.

The next major date is October 8, when the scheduled Spencer hearing is expected to bring the case closer to its final sentencing decision.

Until then, the focus will remain on the penalty phase and the arguments surrounding whether Kosowski should receive life without parole or the death penalty.