The Bronx grand jury probing the Amadou Diallo killing will hear the bulk of the forensic evidence in the shooting this week as community leaders plan to step up protests against police brutality with marches to City Hall.

The Rev. Al Sharpton, lawyer Johnnie Cochran and the Rev. Herbert Daughtry held a rally at Sharpton's Harlem headquarters yesterday, joined by Rep. Jose Serrano (D-Bronx) and other Hispanic politicians to again decry the fatal shooting of the unarmed Guinean immigrant by four cops on Feb. 4.

Serrano said he would pressure the Justice Department to investigate the case for civil rights violations. He also called for police brutality to be an issue in the next presidential campaign.

Diallo's uncle Bob Diallo was stoic as Sharpton exhorted the 400 people at the rally to cheers and applause.

"There is no word to express my grief. . . . Thank you," was all Diallo said.

The Bronx district attorney's presentation to the grand jury begins in earnest this week, when coroners, crime scene officers and ballistics experts are expected to testify to the 23-member panel.

The grand jury is scheduled to spend three weeks hearing evidence, and it may hear from as many as 11 people who allegedly saw or heard parts of the shooting, in which the four cops fired 41 shots.

Last week, as protesters gathered outside the Bronx Supreme Court a block away, the panel mulling charges against the officers heard from Diallo's friends and relatives, roommates and city paramedics who responded to the scene.

Diallo, a 22-year-old un-amred man, was hit by 19 bullets in the vestibule of his Wheeler Ave. apartment building in Soundview.

Street crime cops Edward McMellon, Kenneth Boss, Sean Carroll and Richard Murphy are on administrative duty and surrendered their weapons last week.

Their attorneys haven't said whether they will testify.

City Councilman Jose Rivera (D-Bronx) called the Civilian Complaint Review Board a "rubber stamp" for the mayor, and said Giuliani's "CPR" campaign for cops — Courtesy, Professionalism and Respect — should stand for Cops Practicing Racism.

"The issue of police excessive force . . . is the issue that galvanizes our community like no other," Cochran said. "The police are not above the law. This idea that we can look the other way and say, 'It was a terrible mistake' is wrong. There's been too many mistakes."

Cochran also suggested the Bronx grand jury visit the shooting scene.

"It's a death chamber," he said of the small vestibule. "You would not shoot an animal in there."