New Jersey Gov. Chris Christie signed a law Monday to require out-of-state law enforcement agencies to notify officials here before conducting surveillance, a bill that was prompted by the New York Police Department spying on Muslims in the state.

The NYPD work in New Jersey was exposed when a New Brunswick apartment building superintendent told police about an apartment containing NYPD radios. It turned out to be a safe house for undercover officers coordinating the surveillance.

That revelation was among others in a series of stories by The Associated Press starting in 2011 about the NYPD’s surveillance unit.

New Jersey’s new law, which takes effect immediately, passed by wide margins in both chambers of the state Legislature.

It applies to out-of-state law enforcement agencies but not federal ones. Before starting surveillance in New Jersey, they are required to tell the pertinent county prosecutor who they are following and why, and which officers will be involved. Prosecutors are to pass that information on to state officials.

New Jersey officials can go to a judge to seek surveillance activities that are not reported be halted.

Christie, a Republican who served as U.S. attorney for New Jersey from 2002 through 2008, said the law protects citizens.

“As a former U.S. attorney appointed in the aftermath of Sept. 11, 2001, I strongly believe we need to do everything in our power to prevent terrorist attacks on our country and keep our people safe,” Christie said in a statement. “I also believe we must protect and maintain civil liberties, especially those of the citizens in New Jersey’s Muslim community. This bipartisan legislation will help us reach that balance, and I am pleased to sign it into law today.”

As the top federal prosecutor in the state, Christie oversaw several high-profile terrorism cases and also tried to strengthen ties between Muslims and law enforcement.

(AP)