Homes nearby were evacuated after authorities found what was believed to be a bomb on his property.
Mike and Patricia Smith, who live across the street from Dykes and whose two children were on the bus when the shooting happened, said their youngsters had a run-in with him about 10 months ago.
"My bulldogs got loose and went over there," Patricia Smith said. "The children went to get them. He threatened to shoot them if they came back."
"He's very paranoid," her husband said. "He goes around in his yard at night with a flashlight and shotgun."
"Everybody up the hill tried to avoid him," he said.
Patricia Smith said her children told her what happened on the bus: Two other children had just been dropped off and the Smith children were next. Dykes stepped onto the bus and grabbed the door so the driver couldn't close it. Dykes told the driver he wanted two boys, 6 to 8 years old, without saying why.
According to Smith, Dykes started down the aisle of the bus and the driver put his arm out to block him. Dykes fired four shots at Poland with a handgun, Smith said.
"He did give his life, saving children," Mike Smith said.
Patricia Smith said her daughter, a high school senior, began corralling the other children and headed for the back of the bus while Dykes and the driver were arguing. Later, Smith's son ran inside his house, telling his mother: "The crazy man across the street shot the bus driver and Mr. Poland won't wake up."
Patricia Smith ran over to the bus and saw the driver slumped over in his seat. Her daughter used another child's cellphone to call 911.