Seann Pielia, 19, now faces charges of transmitting a communication containing a threat to injure another individual.
The offending tweet used an image of wedding rings the Nazis seized from Jews at the Buchenwald concentration camp as a way of protesting gun reform legislation.
“Probable cause exists that” Jack Carpenter’s Twitter account “made threats to cause injury and death to Jewish members of the Michigan government,” FBI Special Agent Sean Nicol wrote.
Four classmates were killed and six other students and a teacher were wounded in that attack, the deadliest US school shooting that year.
Lena Epstein, who was raised Jewish, made the comments at a candidate forum at a Baptist church in Holland, Michigan.
One school leader in Michigan left his role as dean of the school after receiving a death threat.
Pro-Palestinian chants hurled at the vice president included "from the river to the sea, Palestine will be free" and "not another nickel, not another dime, no more money for Israel’s crimes."
The mother even initially reported her own bullying to authorities, disguising herself using juvenile language and a VPN.
The survey received over 1,500 entries of words and terms that should be banished for misuse, overuse and uselessness.