Dubbed the "Back the Blue Act" by supporters, the legislation gives officers qualified immunity, meaning they cannot be sued in civil court if they are operating under the law.
The law also protects drivers who unintentionally hit protestors in the street and increases penalties for those individuals blocking roadways. It also defines rioting as "three or more persons assembled together in a violent and disturbing manner," categorizing the act as a Class D Felony.
Much of the law took effect immediately following Reynolds' signature.
"There's no contradiction between world-class investigation and treating victims of crime the way we ourselves want to be treated," Reynolds said. "And there's no contradiction between vigorous policing and the community outreach that builds trust between law enforcement and everyday Iowans."
Supporters say the bill will help police maintain public peace, while those against the new law say it's an infringement on First Amendment rights
The American Civil Liberties Union released a statement calling the law "clearly an effort to shut down public criticism of abuses by law enforcement."
The law comes a year after the passage of a bipartisan police reform bill.