EASTON, Pa. (AP) — A judge was harshly critical of the Pennsylvania State Police on Friday over its attempt to shut down a grand jury looking into how it investigates shootings by on-duty troopers, saying the agency was afraid of public scrutiny.

Judge Stephen Baratta rejected a state police request that he disband the grand jury, ruling from the bench that it will be allowed to write a report and make recommendations on state police policy.

State police argued the grand jury has no authority to investigate whether the agency should use outside law enforcement to probe shootings by troopers. Experts say police shooting investigations should be independent to ensure objectivity and foster public confidence.

"You're saying no one's allowed to tell the state police what to do," Baratta told a state police lawyer at a hearing Friday.

He said the agency was trying to "silence the citizens who are on that grand jury," adding: "You're afraid they're going to make recommendations that you're not going to like."

District Attorney John Morganelli sought the grand jury after state police, citing longtime policy, refused to allow his detectives to take the lead on a probe of a fatal shooting involving troopers near Easton. Troopers shot and killed Anthony Ardo on May 20 after he ignored their commands and attempted to light the fuse of a firework mortar around his neck.

The grand jury concluded in September that Ardo's shooting was justified. At Morganelli's behest, the panel also has been taking a look at state police procedure on investigating trooper-involved shootings and plans to issue a follow-up report.

Richard Zack, representing state police on Friday, argued the panel was limited to investigating crime in Northampton County and had no legal authority to review its policies. Once the panel concluded that troopers were justified in killing Ardo, he said, it should have dropped the matter.

He accused Morganelli of misusing the grand jury.

"We do believe that politics are involved here," he said.

Morganelli rejected the state police contention that he was using the grand jury for political purposes, approaching the bench and thundering into the microphone: "We have a state police agency that wants to obstruct justice and obstruct the administration of law. ... It's outrageous, it's arrogant and it's an effort to intimidate the grand jury itself and the commonwealth's attorney."

Morganelli blamed "brass in Harrisburg" for the dispute and stressed he's long had a productive working relationship with troopers in his jurisdiction. A day earlier, he held a press conference to announce that two troopers were justified in shooting a suspect who had opened fire on them first, critically wounding one of them.

Under state law, the grand jury will submit its report to the judge. He will review the report to make sure the grand jury followed procedure before allowing it to be filed publicly.

State police tried to prevent Friday's hearing from being open to the public. Morganelli and a coalition of media organizations, including The Associated Press, opposed the move, and Baratta ruled the hearing would be held in open court.