Charging that so-called police "death squad" in Prince George's County in 1967 violated civil rights, relatives of two men killed by police and others allegedly lured into committing crimes filed suit yesterday seeking damages of $10.5 million.

The lawsuit was filed in Baltimore federal court under a civil rights law that allows persons to recover monetary damages if their "constitutionally protected right, privilege and immunities" are violated.

The civil action comes a year after the Washington Post reported allegations that a groupp of Prince George's detectives had used police informants to set up robberies at convenience stores in order to catch holdup men and deter crime in the county. Two suspects were fatally shot by police in holdups staged at a Chillum 7-Eleven on June 8 and Nov. 26, 1967.

Among the lawyers filing suit yesterday were Barnet D. Skolnik, who spearheaded federal anticorruption prosecutions in Maryland during the 1970's, and Kenneth Mundy, a highly regarded criminal defense lawyer.

Named as defendents are two present and one retired county policemen, including Lt. Col. Joseph D. Vasco, Jr., a former acting chief of the department; Prince George's State Attorney Arthur A. Marshall Jr. and former assistant county prosecutor Benjamin R. Wolman. Prince George's County and the state of Maryland were also named as defendents.

Vasco, Marshall, Wolman, and the other two officers, "acting together and in concert with others," the suit alleges, "devised . . . a fraudulent scheme to solicit, enlist and entrap police informants and other private citizens into committing 'robberies' at various locations . . ."

The suit goes beyond previous allegations by charging for the first time that Marshall, who has been the county's chief prosecutor since 1962, and Wolman, now in private practice, had "general knowledge" and authorized the alleged "death squad" scheme. The suit contains no specifics, however, to support that charge.

Marshall, who previously denied advance knowledge of the operation, failed to return a reporter's phone calls yesterday. Wolman said he had not yet seen the suit and "any comment would be premature."

The plan they allegedly authorized, the suit said, was for Vasco, Capt. James Fitzpatric, now in charge of police training, and retired Lt. Blair Montgomery, former chief of detectives, to "solicit, enlist and entrap various informants into agreeing to cooperate."

The informants would then, "under explicit instructions from one or more of the police defendents, solicit, enlist and entrap other young men into participating in 'robberies' which had in fact been fully planned by police," the suit alleged.

"Official reports would then be distorted and falsified so as to conceal from the 'robbers' and their attorneys and other law enforcement officers, as well as from the public generally (including the families and friends of the 'robbers') the truth about the 'robberies' and the substantial government involvement in [their] planning and execution," the suit charged.

"It was forseeable that the action necessary to arrest such 'robbers' would inevitably on some occasions "involve the use of deadly force and that some entrapped 'robbers' would therefore be seriously injured or killed," the suit said.

During the High's holdup, police shot and killed William H. Matthews Jr., and 18-year-old Takoma Park youth with no record or prior criminal involvement in Prince George's County, and arrested another man, Marvin Rozier, who was jailed for seven days and received a suspended sentence for larceny.

Five months later, during the Chillum 7-Eleven stakeout, police killed William C. Harris as he fled from the scene and arrested David E. Wedler, who went to prison for two years and four months before being paroled.

As a result of the officials' actions, the suit said, each of the arrested men "lived for 12 years as a 'convicted' felon." Meanwhile, the suit said, Harris' widow and two daughters, now 11 and 14 years old, suffered "consequent pecuniary loss, mental anguish, emotional pain and suffering, loss of society, comfort, companionship and parental care and protection."

Matthews' parents, who knew nothing of the way in which their son had died before the articles were published, suffered similar losses, the suit said.

In past statements, all the individuals named as defendents have denied any wrongdoing in the 1967 occurrences.

An internal county police investigation early last year cleared the police of any misconduct. A four-month Maryland State Police investigation, concluded last October, confirmed the active police role in planning the holdups.

Vasco, whose tarnished reputation from the "death squad" allegations cost him the police chief's job, was in an auto accident early Thursday morning and remained hospitalized in critical condition yesterday.

Said John McHale, sworn in Wednesday as the county's new police chief, "The fact is there was no squad set up to kill people. Maybe things were done in 1967 that would not be done in 1980. Law enforcement has changed."

The suit was filed by Harris' widow, Jacqueline E. Jones, and his two daughters; by Matthews' parents, Mary E. Kosh and William J. Matthews and by Wedler and Rozier, the two men lured by the police informants into committing the holdups.