According to several witnesses Tippit was shot at 1:06 ( Markham 1:06, Benavides a few minutes after 1:00, Bowley arrived at 1:10, ) Lee's landlady, Mre Roberts said that Lee was at the Rooming house at 1:04..... He could not have been at 10th & Patton at the same time(1:04) that Tippit was tailing the man who shot him.
So Markham & Roberts suddenly become the Dynamic Duo after being treated at all other times by you lot as a pair of dingbats.
Testers approx 11 minutes + Roberts approx 1:04 = poor dumb cop getting in the way of warning shots approx 1:15 = Mystery Guest #2