This has been one of the most inept investigations I can recall since the Las Vega shooting. A compromised crime scene, the cars not towed for two weeks, too much speculative information released to the public, and the LEOs just telling people to hide in fear and keep their phones with them.
How about telling people to get a firearm and proper training, to stay in groups (not that it helped these poor students much), stay sober, and not to go anywhere with strangers?
You left out, don’t get dead drunk. (No pun intended).