WASHINGTON (AP) _ Three homeless people who live across the street from the White House are suing the U.S. Park Police for harassment that they say includes being abused, kicked and poked with night sticks.

The lawsuit filed Thursday came after Park Police killed a homeless man from that same park who charged at an officer with a knife and was gunned down on the sidewalk on the Pennsylvania Avenue side of the presidential mansion.

The lawsuit alleges that Marcelino Corniel, 33, who was shot Tuesday morning after he chased U.S. Park Police officer Stephen J. O'Neill with a knife, had been kicked and prodded by O'Neill a few hours earlier.

Corniel was shot by another park policeman, identified today by Lt. Kent Bowen as Jeff Leon Capps. Corniel died Wednesday night after undergoing surgery twice.

The incident was highly publicized because of its locale, the fact that it was captured on videotape and because it was one of a string of violent episodes near or directed at the White House.

In the pauper's suit filed in U.S. District Court, two women and a man who frequent Lafayette Park allege a pattern of harassment by O'Neill and another park policeman named only as ''Keness.''

The officers regularly accused the homeless who sleep in the park of violating a no-camping regulation, the complaint said.

''It has been the custom of officers O'Neill and Keness to accompany their threats with kicks, prodding with nightsticks, and banging signs with nightsticks even when there is no question that those attending are not camping,'' the complaint added.

It alleged ''political or religious animosity'' and said O'Neill's ''abuse of authority ... which preceded the shooting of Marcelino Corniel, is a graphic demonstration of the result of abuse of legal authority.''

They asked the court to order that neither of the two men be assigned to Lafayette Park. At a news conference held later in the park with the White House as a backdrop, the three people who filed the suit asked for a complete investigation of the shooting.

''We feel we are not being treated as human beings,'' said Warren Gaskins.

''They have taken out their frustration on us,'' added Robin Patton, alluding to the much-publicized recent security breaches at the White House.

''My country sent me to Vietnam, killing people,'' said Gregory Parker, ''but I wouldn't gun a man down in cold blood.''

Meanwhile, in Las Vegas, the attorney for Corniel's family said in an interview that ''I haven't heard one person say it was justified.''

The attorney, Milton Grimes, represented Rodney King in another videotaped incident involving police. He met in Las Vegas with Barbara and Samuel Corniel, the parents of the dead man.

He said he will review evidence and videotape of the shooting and plans to go to Washington next week to investigate further and determine whether to file a lawsuit.

Police officials have said the shooting was justified because Corniel had made a move toward an officer with a knife in his hand. But the officer who fired what proved to be the fatal shot has been assigned to administrative duties while the case is being reviewed.

The suit was filed William and Ellen Thomas and Concepcion Picciotto, who ''regularly demonstrate at Lafayette Park for the global elimination of nuclear weapons,'' according to the suit.