The state does not have universal background checks for gun purchases, safe storage laws or a so-called red-flag law — measures instituted elsewhere in response to gun violence.
The sheriff’s office report reveals more about how investigators were able to trace the online post to the teenager’s account, and why they could not definitively link it to him.
The F.B.I. said the teenager denied making threats. His father told investigators that he had hunting guns in the house, but said that his son did not have unsupervised access to them.
Activists, party lawyers and state officials are mobilizing behind a crackdown on a supposed scourge of noncitizens’ casting ballots. Voting rights advocates say the effort is spreading misinformation.