TAMPA, Fla. — A jury on Thursday found Justin McGriff guilty in the 2019 murder of HART bus driver Thomas Dunn.
The jury found McGriff guilty of murder "in the first degree as charged," and determined the murder was both "premeditated and felony murder." On count two, the jury found McGriff "guilty of armed burglary of a conveyance as charged.”
McGriff will be sentenced at 9 a.m. on April 20.
Closing arguments were delivered earlier in the day Thursday. The jury deliberated for about five hours afterward.
The jurors convicted McGriff of fatally stabbing Thomas Dunn on May 18, 2019. Dunn was a Hillsborough Area Regional Transit Authority (HART) bus driver.
Tampa police said McGriff boarded the bus around 4 p.m. armed with a weapon hidden in his right hand. According to an arrest affidavit, McGriff told Dunn, "God bless you" twice before slitting the driver's throat.
The defense did not deny that McGriff's actions killed Dunn but suggested he was insane. The defense team argued he didn't know what he did during the incident or about the consequences.
"Is he a criminal or is he just this diseased guy getting on a bus who had a psychotic break?" assistant public defender Jamie Kane asked.
The defense brought up expert testimony from the week that claimed McGriff exhibited signs of schizophrenia and that it had been apparent before the killing. This follows emotional testimony from McGriff's family this week about a change in his behavior after returning to Oklahoma from California around 2017.
McGriff believed someone was out to kill him, the government was watching him, and he would distance himself, according to family testimony.
The defense also criticized expert testimony from the state. If McGriff had understood his actions and was malingering this whole time, the defense questioned why McGriff would fool his family or succumb to prescription drugs that are "terribly unpleasant."
"He's crazy. That's what it comes down to because nobody knows why he did it," Kane said.
While the state did acknowledge McGriff had a form of mental illness, it argued he knew enough about his whereabouts and his intent to kill. Prosecutors reminded the court that the state eventually did find McGriff competent to stand trial.
The state brought up McGriff's actions on the day of the killing: Concealing the knife on the bus, stabbing Dunn when he's at his most vulnerable, and eventually fleeing from police and changing his appearance afterward.
The state said McGriff disposed of the knife and told police to kill him upon arrest, according to body camera video presented as evidence.
"Why? Because he knows what he did. He knows he's been caught," Assistant State Attorney Ron Gale said. "He'd rather be dead than sitting here in this seat, facing you, the jury of his peers."
Dunn was a father and veteran who died at 46 years old.
Following Dunn's death, both HART and the Pinellas Suncoast Transit Authority (PSTA) installed safety barriers on their buses in an effort to protect drivers.
10 Investigates found that attacks on bus drivers in Hillsborough County spiked the year Dunn was killed, with nearly 500 bus drivers between 2017 and 2019 reporting they had been physically or verbally attacked by passengers.