We don't have a smoking gun on the potential crisis actors though the reporting timeline/living whereabouts for CNN/FBI son looks sketchy and some of Delaney Tarr's pics were disturbing.
While this is still the Crisis Actor Edition here's a link for a Vox interview with Delaney, where she discusses preparation for activism ahead of time with D-Rep Ted Deuch visiting SD High.
A look at Ted's twitter shows his visit and appears to show Delaney and the Bald Headed Student Activists at that meeting. At the least, these students took the message of the meeting about anti gun laws and school violence very seriously. The meeting was also attended by a couple of other local officials, per the twitter post.
More info on Ted Deutch reveals involvement in anti-gun legislation, Pro Dreamer legislation, and regular spots on CNN, NBC denouncing Trump. Typical Dem rep behavior. So far that's all I could dig up on Ted the coincidental narrative preparer, if that is all he is.
https: //www.vox.com/policy-and-politics/2018/2/20/17031050/florida-shooting-parkland-advocacy-gun-control-delaney-tarr