An investigation ordered last month by Prince George's County Executive Lawrence J. Hogan after inquiries by reporters has cleared the county police force of wrongdoing "in connection with... matters" involving what had become known as the "Death Squad."

Associate County Attorney John B. Wynes, who conducted the probe, wrote 18 days ago:

"Based upon my detailed review of each case report, my conversations... and a review of pertinent documentations, there is no basis to believe any general or specific allegations of criminal wrongdoing or other misconduct..."

Nor, Wynes wrote, was there a "reasonable basis to conclude that there exists any material falsity in any official report of the several involved incidents."

Wynes reached his conclusions, he wrote, after interviewing "every former member" of the police detective bureau "deemed directly involved."

He said he also undertook a complete review of several official reports, looked at all pertinent information contained in prosecutors' and personnel files and checked "any other sources deemed appropriate."

Wynes made available to The Washington Post copies of his 11-page report to Police Chief John W. Rhoads, transcripts of 10 taped interviews, some official files from the alleged "Death Squads" stakeouts and disciplinary records of John R. Cicala. Cicala is a retired detective who has described one such stakeout, which resulted in a fatality, as "cold-blooded murder."

When Wynes, Police Chief John W. Rhoads and Hogan visited The Post recently to discuss the results of the investigation, Rhoads suggested that Cicala was disgruntled.

The first page of their report lists 10 questions, including nine related to the "Death Squad". Wynes said he focused on the 10 questions. The last page concerns an unrelated allegation against one of the officers.

All but three pages of the report contain what Wynes said are the relevant facts regarding each stakeout.

Present during several interviews conducted by Wynes, according to the transcripts, was Lt. Col, Joseph D. Vasco, a central figure in "Death Squad" activities and now the No. 2 man in the department.

On one occasion Vasco called one of the men about two hours before the taping of an interview with that man according to the interview transcript.

"There was no reason" for Vasco's presence or telephone contact, Wynes later said, "other than as an icebreaker, to go on the telephone first and introudce me to people I wasn't familiar with, or vice-versa."

Wynes also said that he went through the questions he was going to ask before he started taping. Some of the interviewees reviewed the statements they made in 1967 before the taping sessions began.

"This was so they could refresh their recollections," Wynes said.

Some of Wynes' questions suggested answers. For example, he asked Cpl. Richard Hart about the nickname "'Kill Squad' or anything like that." Hart acknowledged that the detectives were referred to that way.

"But that was more of a macho thing than anything that referred to what you were actually trying to do, I presume. Right?" Wynes asked Hart.

"That is correct," Hart replied.

With Vasco sitting in, Wynes said to Hart at the outset of his taped interview:

"Colonel [vasco] told you a little bit about what this is... what we're trying to do is just get beckground so we can advice the chief, of you know, official position, when this thing, if it does, hits the papers."

Near the conclusion of the interview, Wynes asked Vasco if he had "any other questions he thinks might be pertinent."

The chronological accounts contained in the 11-page report are unattributed. In some cases, they are taken directly from official police reports of 1967.

On several occasions, inerviewees remembered events differently. In his summary, Wynes used Vasco's version where there were conflicts.

According to the Wynes report, Vasco yelled "stop police," before shooting a man in July 1967. Vasco's partner, William R. Cook, told Wynes that he did not remember Vasco saying anything.

Not all participants were interviewed prior to Wynes' report. Those included James Fitzpatrick, now head of the police department's special operation division and author of the official report of one stake-out, and Cicala, the retired detective who said that Vasco was present when the first stakeout was planned.

Wynes said he supsequently interviewed Cicala and others.

"It's obvious there were people who hadn't been inputted who knew something about these things," Wynes said 10 days ago. Wynes said his investigation is continuing. As part of the probe, according to departmental sources, some police employes were interviewed by Lt. Milton B. Crump of the internal affairs section. Crump is a neighbor, close friend and business partner of Vasco in a small lie detector firm.

"We've put together a helluva lot (more) since we last spoke," Wynes said a few days after he handed his report and other material to reporters. As a result, he said, his earlier conclusions had become "absolute convictions now."