Opposing attorneys in the Prince George's County police "death squad" trial completed two days of final arguments before a federal civil jury here today, as the long and bitterly fought case began to wind down.

The $9 million civil rights trial, in which three present and former county police officials are accused of orchestrating a series of five robberies and burglaries in which waiting police killed two suspects, wounded a third and arrested seven others in 1967, is expected to go to the six-member jury late Wednesday--the 87th day of a trial that began almost six months ago on Nov. 15.

Final arguments were peppered with bitter sarcasms and accusations that witnesses on both sides lied throughout the trial. The case has pitted the police officials, including present Assistant Police Chief Joseph D. Vasco Jr., against a group of ex-street informers and a retired county police officer.

Police "created a war zone" and "armed confrontation" by staging the crimes at local convenience stores and instructing informers to recruit participants for the crimes, said Barnet D. Skolnik, one of four attorneys for plaintiffs against police.

"They created a crime and then solved the crime," he said, by shooting or arresting the participants. The participants "were expendable; they were sacrifices," he said.

Police attorney James P. Salmon countered that key witnesses for the plaintiffs were "vindictive" and "prejudiced" against police and vehemently denied the claim that police instructed informers to solicit participants for crime.

"Were they lured into a war zone?" he asked the jury. ". . . I say that every time a criminal goes out there with a gun . . . he creates his own 'war zone.' All the community did by having police stake out the targeted stores was to even the odds."

Time and again, Skolnik hammered at the idea that police recruitment of participants for crime amounted to "outrageous conduct," defined by law as conduct that "shocks the conscience and is offensive to society's sense of justice."

As such, he said, it constituted a denial of due process and civil rights for the plaintiffs in the case--the families of the two men slain in the 1967 incidents plus two of the men arrested in the incidents.

Not so, argued attorneys for the police. The suspects slain or arrested at the staked-out stores all had a "predisposition" to commit crimes and fully intended to rob or burglarize various stores in the county, the attorneys said.

During the trial, Vasco and other defense witnesses denied instructing informers to recruit participants, saying, rather, that the informers came to them with tips about planned holdups and other crimes. Police testified that they provided informers a getaway car in one incident and a store key in another but contended such "instrumentalities" are legal when the crime has already been planned by the suspects.

They also testified they instructed informers in some cases to change the time or location of a planned robbery to minimize possible harm to innocent bystanders.

Skolnik argued to the jury on Monday that the possible criminal "predisposition" of the plaintiffs in the case is irrelevant and does not diminish the "outrageousness" of the police action, which he said was "creating the crimes" in the first place.

"Even if you think those plaintiffs are all young Al Capones," Skolnik said, "you can consider the outrageousness of police conduct . . . Even Al Capone has constitutional rights."

But "does a person have a right to stick a gun in the ear of a store clerk," countered Salmon, referring to one of the so-called "death squad" incidents in which suspect William H. Matthews, 18, was shot and killed by police at a High's Dairy store in Adelphi on June 8, 1967, after police say he pointed a pistol at an officer posing as a clerk.

In the other fatal incident, William C. Harris, 25, was shot and killed Nov. 26, 1967, after police said he fled from a 7-Eleven store he had just robbed in Chillum and was pointing his pistol at an officer staked out nearby.