On Sunday afternoon, Terrell Cowherd's father undertook the somber duty of going through his son's things and offering an impromptu elegy to the reporters who showed up.

"He always said Dad and Mom, thank you for everything," he said. "Thank you for all you've given me, thank you for all you've done. And you know what I would say to him? Thank you, son."

Cowherd, 26, two years out of Prairie View A&M with an engineering degree, 10 months into a job at Luminant, was on Lower Greenville early Saturday morning when a fight broke out in front of Club Kush hookah lounge. He stepped into the fray to break up the fight and calm things down. "Mr. Cowherd is a good Samaritan," as Major Jeff Cotner of the Dallas Police Department later put it.

Julian Terence Martin Jr., 23, was one of the combatants. He turned his attention to Cowherd when he stepped forward and began to taunt him. Dallas police released a brief video clip:

Martin and a friend, 23-year-old Jerry Brown, punched Cowherd several times. Then, as Brown held Cowherd from behind, Martin pulled a knife from his pants pocket and stabbed him, again and again.

"As Terrell laid down, blood gurgling in his lungs, blood coming up in his lungs, the guy punched him. When he was fighting for his last breath," Cowherd's father later marveled. "What kind of human being is that?"

Cowherd was taken to Baylor Hospital, where he was pronounced dead.

Police found Brown loitering in a parking lot about a block away, the gash on his hand a dead giveaway. He was arrested and treated briefly at Baylor before being taken to DPD headquarters for questioning. Martin was identified from several videos -- surveillance and cell phone -- taken at the scene.

Both men are currently in jail on murder charges. Cowherd's father hopes they stay there.

"There is no way they should ever, ever see the light of day again," he told NBC 5. "This could be your brother, your sister, your mother, your daughter. You're just going to come out and snuff somebody's life out who's never done anything to anybody in his life."