See this article by KCCI-TV 8.
The Iowa Senate has passed the bill, and it now goes back to the Iowa House after a Senate amendment.
An online article by USAToday carried this: "More than 30 states allow teachers or other K-12 school staff to be armed in at least some circumstances, according to the National Conference of State Legislatures." One Senator said, ""Seconds count when law enforcement are minutes away even in the quickest response."
All 30 Republican Senators voted in favor. All 14 Democrat Senators voted against it.