Sort:  

Initial reports (those Live/Breaking news reports as it were happening) stated 'It has been confirmed that the gunman is a student who was in class at the school earlier in the day', (that was told to the media directly from the Broward Police followed by 'they have his home and work address').
With that in mind, plus people hypothesising that it seemed like they were carrying a body in the bag, and after watching the video repeatedly, I can't shake the notion that maybe there is a small possibility that it could be Cruz in the bag, either drugged, unconscious etc.
It would fit in with the blonde witness statement of talking to him mid-shooting, and explain how they caught him so fast. Especially when he was unidentifiable to all shooting witnesses because of his mask/identity obscuring clothing during the shooting. (So how did they know it was him so quickly?)
It wouldn't be hard to lure someone with ASD/ADHD (autistic traits make you socially naive to people's intentions), especially if he had been pre chosen as the 'Perfect Patsy'.
It may sound crazy, but it's a thought train worth considering until someone can rule it out.