Prosecutors charged Johnson, 49, of Grandview, Mo., with involuntary manslaughter in connection with the deaths of Larry Gaunt, 59, and his 14-year-old granddaughter, Sierra Gaunt.
The two were cycling on Raytown Road last August when they were struck and killed by Johnson's pickup.
Prosecutors argued that Johnson could have avoided hitting both cyclists.
One of their witnesses was a Grandview police accident reconstruction officer who said that the grandfather and granddaughter were heading the same direction as Johnson's pickup. That officer said Johnson veered off the road, and when he tried to get back on the road, he overcorrected.
Defense attorneys argued that Johnson could not have avoided them because the two cyclists pulled out in front of him. Lester Dickey, a family friend, said he could not understand why prosecutors filed a criminal charge against Johnson.
Johnson claims the two bicyclists swerved in front of him, but witnesses who took the stand Tuesday morning said that wasn't the case.
In fact, one of them testified that he thought William Johnson was going to drive off because he started up his truck again.
"i asked him, I said 'Man, what are you doing?' and he said, 'I'm trying to turn my truck around.' I said, 'Man, it's too late for that,'" said Eugene Looay.
Johnson is expected to take the stand in his own defense as is his 12-year-old son who was with him at the time.
Greer also said that Johnson, of Grandview, will take the stand Wednesday and testify the Gaunts were riding on the shoulder and swerved in front of his truck. Johnson will testify that he braked but was unable to avoid striking them, according to Greer’s opening statement.
Edwards, however, said that evidence will show that Johnson was speeding and that he never changed lanes to avoid the collision.
Witnesses this morning included three motorists who witnessed the collision or happened on it immediately afterward. Several police officers also testified, as did Brad Gaunt, son of Larry Gaunt and Sierra’s uncle.