Defense attorneys today challenged claims of retired Prince George's County policeman John R. Cicala that a so-called police "death squad" improperly staged a series of holdups in 1967 in which two men were killed and a third was wounded by police.

At one point in the $9 million civil trial against alleged "death squad" members in federal court here, Deputy County Attorney Michael O. Connaughton produced an official police photograph taken at one of the holdup scenes, contending it showed Cicala looking toward a bullet hole that he subsequently claimed did not exist.

Connaughton and other defense attorneys say the bullet hole was made when a holdup suspect at the High's Diary store in Adelphi fired his pistol at police staked out at the store, justifying police in firing back and killing the suspect, Wiliam Hunter Matthews, 18.

"Did you ever tell anybody the bullet hole didn't exist?" Connaughton asked Cicala.

"I believe I did," Cicala acknowledged.

Under further questioning, however, he said that he could not recall saying it was therefore unnecessary for police to shoot Matthews.

When Cicala examined the photo showing him looking toward a cigarette display case pierced with a small hole, he said he was "referring to a hole in the store refrigerator." Defense attorneys contend there was no bullet hole in the refrigerator and that Cicala was confused.

Defense attorneys attempted to chip away at Cicala's credibility throughout today, as the trial before a six-member civil jury moved into its fifth week.

Survivors of the two men killed in the 1967 holdups, plus two other men arrested during the incidents, filed a $9 million damage suit against three members of the alleged "death squad," claiming that the three had directed police informants to recruit participants for bogus holdups orchestrated by police.

Also named in the suit are Prince George's County State's Attorney Arthur A. Marshall Jr. and former assistant State's Attorney Benjamin R. Wolman, who are charged with authorizing the police actions.

Cicala, 49, testified last week that he had been a member of the "death squad" from June 1967 until November 1967, when he was fired from the police department for refusing to participate as a store clerk in one of the staged robberies. He later was reinstated on the police force and retired in 1977.

He testified that the June 8, 1967, High's robbery in which Matthews was shot and killed had been planned by police "from A to Z." Cicala said that retired Lt. Blair Montgomery and Det. Joseph D. Vasco, Jr., now second highest ranking official in the county police department, directed informant Gregory Gibson to recruit a "couple of patsies" for the holdup.

They then provided Gibson with a getaway car and selected the date, time and location of the robbery, Cicala testified.

Matthews, one of Gibson's two recruits, was shot and killed after he pointed a pistol at the head of an officer posing as a clerk in the store and then fired wildly toward the rear of the store when other police shouted to him to halt, defense attorneys say.

After that incident, Cicala testified, he refused to participate in another planned holdup of a 7-Eleven store in Cheverly on Nov. 24, 1967. He said he told his superiors that he feared for his life, but also felt that the "set-up" was "legally and morally wrong."

In the Nov. 24 holdup, suspect Pedro Gonzales, 34, was shot and wounded by police. Two nights later, on Nov. 26, 1967, a third suspect, William Clyde Harris, 25, was shot and killed at another 7-Eleven store in Chillum staked out by police.

Defense attorneys today tried to contradict Cicala's testimony, confronting him with earlier conflicting statements he had made in depositions and interviews with state and county officials investigating the alleged "death squad" incidents.

At one point, for example, he testified that he could not distinguish between police shotgun fire and possible "small bore" fire from Matthews' pistol in the June 8, 1967, High's robbery while he was positioned on the roof of the store. Defense attorneys contend this suggested that Matthews may not have fired his pistol at all.

Today, however, defense lawyers produced an interview Cicala had had with Associate County Attorney John Wynes early in 1979, in which Cicala said that he had heard small bore fire almost simultaneously with heavier shotgun fire.

"Your memory . . . it keeps changing," said defense attorney James P. Salmon at one point.

"I did not ask to testify in this case," retorted Cicala at another point. He declared that "I'm trying to do the best I can," noting that the "death squad" events occurred more than 15 years ago.

The allegations first came to light in 1979 in a series of articles in The Washington Post. The survivors of the incidents subsequently filed their lawsuit against the alleged members of the squad, contending that their actions violated due process provisions of the 14th Amendment.