The man who is the spitting image of Mr. Billy Lovelady is either
a) Mr. Lovelady, standing on something
b) A Lovelady lookalike, who happens also to be current holder of the Dallas's Tallest Man prize.
Tough one............

Not you're not still doing the Lovelady-On-A-Box routine, are you?
That's almost as good as the In-The-Building-Is-Outside-The-Building routine.
Or your latest one - the old Prayer Man/Prayer Woman Switcheroo.
As I have this man down as the potential shooter, it's interesting to note his passing resemblance to Oswald.
As for the tallest man in Dallas - I reckon Dougherty was around 6'4" at the time of the assassination. There's no reason to believe the man in Chris's pic is any more than that.