Prince George's County Executive Lawrence J. Hogan said yesterday that he believes county police "probably entrapped people" into committing armed robberies in 1967.

However, Hogan suggested that too much time has passed since then to determine exactly what happened and who was responsible.

Hogan also rejected the notion that police planned to kill two robbery suspects during stakeouts of the robbery sites.These deaths were the basis of the so-called "death squad" legend that was the subject of several articles in the Washington Post last month.

Hogan has asked for a state police investigation of the Post reports. The FBI and the Prince George's County prosecutor rejected similar requests by Hogan last month.

The FBI said too much time had elapsed. Prince George's State's Attorney Arthur A. Marshall said an investigation by his office would be inappropriate because he was the prosecutor in 1967 and "because I believe the allegations are completely without substance."

Hogan told Post editors and reporters yesterday, "There is some doubt about where certainty lies, but this happened 12 years ago. At this point, does it really matter?"

Both a former detective on the "death squad" and a police informer who worked with them told The Post virtually identical stories about a June 1967 armed robbery -- during which an 18-year-old robber was killed by police -- which the two sources said was set up by police.

That robbery and two others in 1967 ended in police shootings, including one other fatality. The police actions that resulted in the deaths, according to the former detective and others involved, were taken to stop a rash of convenience store holdups in the county.

"I think there was entrapment involved," Hogan said, "but that's how the game was played then... I would venture that every police department in the United States did the same thing... If true, it's disturbing, but this story's not new. All I'm trying to do is start over in 1979."

The Post sources said that then-detective Joseph D. Vasco, now a highranking police official, arranged the robbery of an Adelphi High's store during which a suspect was killed. Vasco has denied any such role. Police Chief John W. Rhoads said the Post stories were based on reports from "unreliable sources."

Acting on Post inquiries prior to the articles, Hogan ordered an internal investigation of the allegations. He then provided this newspaper with copies of the preliminary report and transcripts of 10 interviews on which it was partly based.

Hogan refused yesterday, as he has before, to release the final 30-page report of Associate County Attorney John B. Wynes, the police legan adviser who conducted the internal investigation. It would serve "no purpose" to make public the final report, he said. Hogan further asserted that the Post stories were "unjudicial."

He had cooperated with The Post initially, Hogan said, because, "my goal was to killthe story.... My goal was to save the Prince George's County Police Department some unneeded embarrassment, even if there was wrongdoing in 1967.... I was hoping the story wouldn't appear."

"If you hadn't run your story yet, I'd give you the whole report," Hogan said. "My police department has already sustained a body blow.... All we would do is get another big story bringing this to public attention again.... I don't want any more stories."

Before expressing his belief that the Post stories were essentially accurate, Hogan challenged the veracity of the newspaper's sources. One source, he said, had given police probers a version of events "diametrically opposed" to what he told The Post.