He Walked on to a Bus and Told the Driver 'God Bless You.' Then He Slit the Innocent Victim's Throat.

A man walked onto a bus and went up to the driver and said, “God bless you.” He then slit the throat of the innocent victim.

The reason for the killing remains a mystery, but there is no question the killer will now spend the rest of his life behind bars.

A Florida judge sentenced Justin McGriff to life in prison for killing Thomas Dunn. He was previously convicted of first-degree murder.

On May 18, 2019, McGriff boarded a Hillsborough Area Regional Transit Authority bus in the Tampa area. McGriff had a weapon hidden in his right hand, according to WTSP. McGriff then twice told Dunn, “God bless you” before slitting his throat.

During his trial, defense attorneys tried to claim Dunn was legally insane and suffered from schizophrenia, WTSP reported.

McGriff believed someone was out to kill him and the government was watching him, according to the station.

"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 jury.

However, prosecutors contended McGriff knew enough about his whereabouts and had an intent to kill.

During the sentencing hearing, Dunn’s brother, Michael Dunn, tearfully spoke about how the pain hadn’t eased in three years, according to WTVT.

"Knowing that his kids have to grow up without him is probably the hardest part. I miss him every day," Michael Dunn said.

Judge Christopher Sabella also had strong words for McGriff before he sentenced McGriff to the mandatory life sentence.

"The common thread in all of these cases is a clear mental health issue, an underlying mental health issue that was there before some innocent person had to lose their life. The innocent person today is Thomas Dunn, and it is sad,” Sabella said. It’s sad that our system of mental health has failed us.”