AFTER THE RIOTS: THE SEARCH FOR ANSWERS : Grand Jury Set to Look Into King Beating : Inquiry: Federal investigation extends to all officers who witnessed the incident. Motorist’s civil rights are at issue.

A federal grand jury is expected to hear testimony today in the government’s investigation into whether four Los Angeles police officers were guilty of civil rights violations against black motorist Rodney G. King.

Local and federal law enforcement sources said new subpoenas have been issued in the case, and a Los Angeles Police Department source said the federal government is reviewing the actions of the four officers tried in the beating of King and of almost two dozen other officers who were bystanders at the scene.

Last week, U.S. Atty. Lourdes G. Baird took the unusual step of announcing that a grand jury had been convened and subpoenas had been issued, but she would give no further details.

The LAPD source said officials of the department’s Internal Affairs and Robbery-Homicide divisions have been asked to turn over “all tangible pieces of evidence” to the federal investigators, including the personnel records of all those involved, and “even uniforms and shoes worn that night.”

Police Lt. Patrick Conmay and Sgt. Robert Ontiveros, two Foothill Division supervisors, have been asked to submit to FBI interrogations, the source said.

“A very broad and very comprehensive subpoena for LAPD records dealing with the criminal and administrative investigations of the entire Rodney King incident” has been issued, the source also said. “I can infer from all of this that not only is the focus on the four defendants, but (on) all of the bystanders. . . . So, that’s going to scare a lot of cops.”

A federal source said it should not be assumed that the bystander officers are targets of the investigation, however.

Prosecuting the bystanders would enlarge and complicate the case and make it more difficult to present to a jury, said Washington attorney Daniel Rinzel, who oversaw more than 200 brutality prosecutions during the eight years he headed the criminal section of the Justice Department’s civil rights division.

A source close to King confirmed that the FBI has asked his attorneys for various documents. The source said the federal agency wants the witness lists for King’s pending civil lawsuit, as well as the names of those who can account for King’s actions between the time he stepped out of his car and when the videotaping of the incident began.

Other sources said Justice Department attorneys also have requested an interview with California Highway Patrol Officers Melanie and Timothy Singer, the married couple who saw the beating of King and testified at the Simi Valley trial.

The FBI said that it opened a federal civil rights investigation a few days after King was beaten the night of March 3, 1991. It said that even before the verdicts were announced last week, it had done considerable work on the case and had interviewed officers of the Foothill Division, which patrols Lake View Terrace, where the incident took place.

The FBI already has obtained numerous LAPD documents about the incident, some voluntarily provided by the LAPD and others obtained by subpoena, according to sources.

In addition, the FBI has interviewed many other witnesses, including King, people who saw the beating and medical personnel who treated King afterward.

Assistant U.S. Atty. Michael W. Emmick, one of the attorneys involved in the King probe, would not comment. Neither would Assistant City Atty. Linda Lefkowitz, who defends police officers in civil liability cases.

She said she is under strict federal orders not to disclose any portion of a recently issued subpoena.

“I’ve been told the subpoena is not a matter of public record,” she said. She also said it would be improper to say when any grand jury session would occur.

A Los Angeles Superior Court jury of six men and six women found Officers Stacey C. Koon, Timothy E. Wind and Theodore J. Briseno not guilty of all charges against them in the Simi Valley trial.

Officer Laurence M. Powell was acquitted of assault and of filing a false police report. The jury was hung as to whether Powell used excessive force, with eight members in favor of acquittal and four for conviction. Dist. Atty. Ira Reiner has not said whether his office will retry Powell on that charge.

U.S. Atty. Gen. William P. Barr has said on several occasions that a federal criminal indictment could be lodged against the four officers, even though all but Powell were acquitted.

The officers could be prosecuted under a federal statute that prohibits unlawful acts committed “under color of state authority,” or under the federal law against conspiring to violate the civil rights of any person.

Koon’s lawyer, Darryl Mounger, said he had not heard about the subpoenas, but he added: “It doesn’t surprise me.”

Mounger lambasted President Bush for announcing the federal probe on television in a nationwide address Friday night. He said it would be “a travesty of justice” if his client and the other officers were indicted on federal charges.

Mounger said there was no place where his client could get a fair trial because of all the publicity about the Simi Valley verdict.

Attorneys for Powell, Wind and Briseno could not be reached for comment.

Times staff writer Ronald J. Ostrow in Washington contributed to this story.