CHICAGO — Journalistic heavy hitters lent support Monday to an effort to toss out a prosecutor’s subpoena for notes, grades and other materials from Northwestern University journalism students, an investigator and their professor in connection with the case of a man the students argue was wrongfully convicted.

The Cook County state’s attorney’s office also subpoenaed videos, grading criteria and more from a Medill Innocence Project investigation into the case of Anthony McKinney, convicted of the 1978 shotgun murder of a security guard.

Attorneys for the school have fought the subpoena, saying the students, Professor David Protess and private investigator Sergio Serritella were all working as journalists when they gathered affidavits, documents and videotaped interviews.

On Monday, an attorney representing the Chicago Tribune, The New York Times, the Chicago Sun-Times, CBS News, The Washington Post and the Hearst Corp._in addition to a dozen more newsgathering organizations_filed a brief in Cook County Circuit Court opposing the forced surrender of the material.

“I think the point of the (filing) is to explain to the court the importance that a large number of journalism organizations give to the position that Northwestern and Mr. Protess are taking here,” said the media group’s attorney, David Sanders of the Chicago-based firm of Jenner and Block. “These are important issues.”

In November, the state’s attorney’s office filed documents in the case laying out allegations by various witnesses of bribery and improper influence exerted on the part of the Medill Innocence Project. The students, Protess and Serritella all deny the accusations.

In response to that November filing, attorneys for Northwestern University filed on Monday another brief in support of the judge throwing out the subpoena.

In that brief, attorneys did not respond to each of the accusations in the state’s attorney filing, instead dealing with various legal issues.

But the Northwestern filing did reiterate the Innocence Project’s previous assertions that a questioned travel payment for a witness was not a bribe, as suggested in the prosecutors’ last filing.

Protess, the Northwestern professor who created the Medill Innocence Project, said he was pleased to have backing for his argument that reporter shield laws protect his students.

“We received support from the national media as well as our friends in the local media for the positions we’ve taken all along,” Protess said after Judge Diane Gordon Cannon ruled that she would accept the amicus, or, friend of the court, briefs.

Also filed Monday was a support brief by organizations including the Student Press Law Center and the Society of Professional Journalists.

Erin Bolan Hines, of the Chicago-based firm of Baker and Hostetler, represented student groups who also oppose the release of the Medill Innocence Project information.

• Georgia Garvey