Like i said in the last thread, these were probably a bunch of yuppis that went into the forest during summer, saw some poisonious berries thinking OH FUCK look we found some berries! lets dig in!
Fed some to the kid and the dog, yes you can feed 1 year olds food like that its a berry you can fucking gum it.
Turns out they probably ended up eating Anatropa bella donna berries, IE deadly night shade, probably ate like 5+ each. Either the kid or dog died first, they panniced, caused their blood and heart rate to increase, moved the poison faster through their system, and then dropped dead.
The only other thing would be if they died from ricen, because that wont show up on a toxicology report unless you specifically look for it.