Yet his fiancee, Rhonda Rouer, testified that Dunn had never mentioned any weapon to her -- be it a shotgun, a stick, a barrel or a lead pipe -- unlike what Dunn had said.
In fact, police found a basketball, basketball shoes, clothing, a camera tripod and cups inside the teenagers' Durango, but no gun.
And Dunn himself never called police. The first contacts he had with them were at his home in Satellite Beach -- 130 miles south of St. Augustine -- as he was being apprehended.
Arguing that he wasn't in a rational state of mind, Dunn admitted, "It makes sense that I should have (contacted authorities). We didn't. I can't tell you why."
Echoes of Trayvon Martin and George Zimmerman
Some were quick to compare Dunn to George Zimmerman, who ultimately was acquitted of murder for the shooting of Martin.
Martin's own parents were among them, claiming Davis' killing is another reminder that, in Florida, "racial profiling and stereotypes" may serve as the basis for illegitimate fear "and the shooting and killing of young teenagers."
But Dunn's defense attorney, Strolla, told CNN's Chris Cuomo on Friday that the Zimmerman and Dunn cases aren't so similar.
There was a physical confrontation between Zimmerman and Martin, and police gave Zimmerman the benefit of the doubt about defending himself, Strolla said.
"My client did not wait to become that victim," he said. "My client did not wait to either get assaulted by a weapon or have someone potentially pull a trigger," he said.
Though a weapon was never found, Strolla maintains the youths could have had one and somehow ditched in and around the gas station. Regardless, the key point was that Dunn believed they were armed and that his life was in danger.
"Now, does it sound irrational? Of course it sounds irrational. But have you ever been in that situation?" the lawyer asked.
After Saturday's night decision, it seems unlikely -- unless he wins on appeal -- that Dunn will ever be in that or many other situations again. Instead, spending the rest of his life in prison seems a more likely outcome.
Strolla said on Saturday the four convictions leave him with regret, even as he said he couldn't immediately think of anything he'd do differently in the case.
At the same time, the prosecution didn't manage a conviction on what was by far the biggest charge: first-degree murder.
This mixed bag means that no one can fully celebrate the jury's decision.
"Everybody lost something in this," the lawyer said.
His client "will live to fight another day" in court, but he and his loved ones are suffering now. Strolla acknowledged, too, the pain felt by Davis' family.
Especially on Sunday, which would have been Davis' 19th birthday.