Trial Underway for Man Accused of Killing White Rock Jogger

It was an emotional day for witnesses as they described coming into contact with defendant Thomas Johnson just moments before 53-year-old David Stevens was brutally murdered while out for a run.

"I looked up at him and said good morning and he glared down at me with the most evil eyes, I've ever seen, I've ever seen," said Sharon Callison, who was out walking with a friend on the White Rock Lake trail the morning of October 12, 2015.

Callison said they came in contact with a man wearing a red hoodie and a demeanor she'd never forget.

"I never felt such a presence of evil, to be honest. His eyes were just cold and hard and just evil looking -- and I told Annette that man is mean and evil," she said.

Also on the trail at the time was 53-year-old David Stevens, out for his morning run. Biker Brandon Davenport testified how he came upon a scene where he saw Stevens being brutally attacked by another man with a machete.

"It was one-handed, it was as if trying to cut like chop wood, like all of the way up and back down, I saw six or seven of them, just massive, over-the-head swings, coming back on the person on the ground, onto their neck," Davenport said.

Former Texas A&M football player, Thomas Johnson later told police he attacked Stevens randomly because he was upset with his living situation at the time. Annette Luscio called 911 when she saw Johnson acting erratic both before and after the attack.

And he starts yelling at me saying, 'Give me your phone, give me your phone,' and I said, 'I am not giving you your phone,'" Luscio said.

The medical examiner, paramedics, Dallas police officers and witnesses also testified. Officer Jeff Newhouse described to jurors how he saw Johnson on the scene, claiming that he was the one responsible for the crime.

I saw him sitting down hugging this pillar right here, facing this direction, and he kept repeating over and over that he had committed capital murder. He said it approximately 10 or 12 times," Newhouse said.

Johnson was found incompetent to stand trial in 2016 and was sent to a psychiatric hospital. He was later found fit to stand trial. The defense is pleading not guilty in this case. If convicted, Johnson could face anywhere from five years to life in prison.

Judge Amber Givens-Davis dismissed the court for the day Monday around 3 p.m. She asked jurors and attorneys to arrive at 8:15 a.m. on Tuesday and to be ready to begin testimony at 8:30 a.m.

The wife of a man who was killed at random while running around White Rock Lake two weeks ago took her own life Sunday, authorities said.

Stevens' wife of 25 years, Patti, later took her own life. In the days before her suicide, Patti Stevens told The Dallas Morning News that she felt lost without "the love of my life."

Johnson is a Dallas native who attended Skyline High School and played football for Texas A&M in 2012. He disappeared mid-season and wasn't seen again until he appeared at his family's Dallas home three days later.