That a kid this age was shot in that neighborhood isn't a surprise. St Louis City and County residents are EXTREMELY fed up with the DA's catch and release policies of juveniles who are regularly committing serious felonies with zero consequences. There was even a case a few months ago of a kid arrested twice by the same officer for the same charge (armed carjacking) within a week.

Kids know there are no consequences, so they steal cars, drive to other neighborhoods and simply walk down streets during the middle of the night checking every car or garage door they encounter to break into vehicles/garages and steal what they can. They're usually in groups and armed. STLMPD also regularly (a few times a week) post images of narcotics/firearms confiscated during traffic stops, house raids ect, almost always stolen Glocks (often with "switches" that make them full auto) with extended mags, AR pistols and or Draco AK pistols.

Armed juvenile criminal action in STL city is a massive problem resulting from years of zero to little enforcement and also no consequences for parents who allow their kids to repeatedly commit criminal offenses.

That being said, there was no reason to cover it up. A juvenile fleeing from a stolen vehicle matches a common profile and if he really did have an object in his hand, it wouldn't have been hard to make the case that the officer believed a threat was present at that time. I can remember two other incidences (IIRC) where a suspect holding a cell phone was mistaken to have a gun and was shot by police, so it wouldn't have been unprecedented.