A federal civil jury today absolved three present or former Prince George's County police officials of wrongdoing in a series of so-called "death squad" incidents in 1967 in which two suspects were shot and killed by police and several other persons were arrested.

The jury of three men and three women returned the verdict late today after about six hours of deliberations in the nearly six-month-long trial.

The police officials, including present Assistant Chief Joseph D. Vasco Jr., had been sued for $9 million by families of the slain suspects and two of the arrested suspects. They accused the officials of instructing informers to recruit participants for a series of five robberies and burglaries in which waiting police killed or arrested the participants and let the informers "escape."

A jubilant Vasco and the other defendants leaped to their feet and embraced each other and several fellow officers after U. S. District Court Judge Herbert F. Murray read the verdict clearing the three men of accusations of civil rights violations.

"I'm happy it's over. I'm thanking God it's over," said Vasco, whose future with the police department reportedly was tied to the outcome of the trial. For months, it has been rumored that Prince George's County Executive Parris Glendening would name Vasco chief of the department if he was cleared.

Glendening would not comment on those reports tonight, saying, "It's our intention to look at the whole department, from top to bottom." He added that "I'm kind of pleased for the people involved as well as for the county. The whole thing has dragged on to the point of distraction, not doing anyone any good."

Capt. James Fitzpatrick, another of the accused officers, with tears brimming in his eyes, told reporters outside the courtroom, "I'd rather work the streets than be in that courtroom . . . . What a six months. I pray another policeman will never have to go through this."

Jurors refused to talk with reporters about how they reached their verdict. They shook hands with Vasco and the other defendants, wishing them well.

The verdict came with a swiftness that surprised attorneys on both sides. None of the family members of the slain suspects or other plaintiffs, who were present for much of the long and complex case, was present when the verdict came.

The verdict also absolved the Prince George's County government of wrongdoing. Plaintiffs in the case had accused the county of failing to train and supervise the officers properly.

While the "death squad" incidents occurred almost 16 years ago, they did not come to general public light until 1979, when The Washington Post published a series of articles outlining the allegations.

Families of the slain suspects and the arrested suspects filed their $9 million lawsuit after publication of the articles, contending the police actions violated their civil rights and deprived them of due process under the 14th Amendment.

In The Post articles, county police said that in 1967 Vasco and other detectives in the department's Hyattsville substation were known in police circles as the "death squad" because of the slayings. Use of the term "death squad" was banned at the trial by Judge Murray at the request of police lawyers.

Throughout the trial, the three police defendants--Vasco, Fitzpatrick and retired Maj. Blair Lee Montgomery--denied they instructed informers to recruit participants for crimes.

Rather, they said, the informers came to them about tips of planned robberies or burglaries of convenience stores in the Hyattsville area, and detectives then routinely staked out the targeted stores.

Much of the trial pitted the word of the three officials against that of informers. The informers contended that the police officers, particularly Vasco, pressured them to find participants and set up crimes in exchange for promises by the police to help drop pending criminal charges against the informers.

Each side claimed the other lied throughout the trial.

The two persons killed in the incidents were William H. Matthews, 18, shot by police staked out at a High's Dairy store at 9101 Riggs Rd. in Adelphi on June 8, 1968, and William C. Harris, 25, killed as he fled from a 7-Eleven store at 1331 Chillum Rd. in Chillum on Nov. 26, 1967.

Both men, armed with pistols that they fired or pointed at police during the holdups, were slain only after they had been ordered to halt, police witnesses said in the trial.

Earlier in the trial, Prince George's County State's Attorney Arthur A. (Bud) Marshall Jr. and Benjamin R. Wolman, a former assistant prosecutor, were released as defendants. They had been accused of approving the alleged police actions in the death squad incidents. Judge Murray ruled that the plaintiffs had failed to prove this.

Marshall, reached at his office in Upper Marlboro, said the verdict "didn't surprise me." He said he and Wolman will "very probably" file suit against the plaintiffs and their attorneys.

Police Chief John E. McHale Jr., who presumably would lose his job if the rumors about Vasco come true, said Glendening has told him he was "in no hurry" to make a decision. McHale added, "I hope he Glendening will do it on the merits of the person, and that this trial won't have anything to do with it."

McHale added, "It'll be nice to have one of my deputy chiefs back."

The jury began deliberating earlier this week after hearing testimony from nearly 60 witnesses and receiving more than 100 pieces of documentary evidence during 88 days of a trial that began in November.

Judge Murray read a 36-page set of instructions to the jurors and armed them with a complex 48-page verdict form on which they were to assess possible monetary damages.

"I'm extremely pleased," said Montgomery, retired from the police force 10 years and now living in Florida. "We had an excellent jury. They were honest and very intelligent."

Edward Camus, one of several attorneys the county hired to defend the police and the county, called the newspaper stories that triggered the lawsuit "irresponsible journalism."

"Determining the facts in a case is the ultimate goal of investigative journalism and they the two Post reporters who wrote the stories didn't do that. They determined the result that they wanted . . . and filled in the blanks."

Barnet D. Skolnik, leading attorney for the plaintiffs against the police, said of the jury, "They did what they thought was right, I'm sure." He indicated an appeal is likely.