Perot’s Penchant for Suspicion Not New : Security: For two decades he has said he and his family were targets of enemies ranging from murderers to the media.

Ross Perot first charged that Republican dirty tricksters were trying to sabotage his candidacy last spring, but his penchant for conspiracy theories and personal security goes back more than two decades.

Perot believes that he and his family have been the target of murderous bands dispatched by Hanoi and American drug-dealing cartels. He contends that senior Ronald Reagan Administration officials engaged in a bizarre global plot involving drugs, guns, money-laundering and covert operations on three continents. He seems to believe that the American media are in league to destroy him. He has accused business competitors of trying to bug his offices and has repeatedly investigated employees and others whom he was convinced were trying to rip him off.

Perot’s suspicions evidently extend to electoral politics. His eruptions against the Bush Administration on Sunday and Monday--when he said he withdrew from the presidential race last July to derail a GOP smear of his daughter--parallel his accusations from last April. Then, he accused the Bush campaign of planting negative stories about him and alleged that “everything you see the Republican Party doing to me is coming straight from the top.”

Then, as now, the Administration called him “paranoid.”

But a former Perot aide disputes that. “Paranoid suggests there’s no basis for fear and I think he does have reason to be concerned,” James D. Squires said in an interview. The GOP is “capable of doing anything.”

In late June, in Perot’s first and only full-blown press conference of the first phase of his campaign, the Dallas billionaire lashed out at Bush for conducting “a carefully orchestrated plan to try to damage me” by spreading false stories.

The only concrete example of GOP dirty tricks that Perot cited on that occasion was an alleged attempt by Republican operatives to unearth the will of his late mother, Lulu Perot. Bush campaign officials dismissed the charge as “preposterous” and Perot never raised it again.

Then, as now, Perot refused to provide evidence to substantiate his dirty tricks charge, saying only that the White House campaign to discredit him was modeled on the propaganda efforts of Adolf Hitler.

Former Perot spokesman Squires denied that the independent candidate is consumed by delusions of persecution.

Squires said that Republicans in particular have elevated campaign dirty tricks to a high art. He cited the State Department investigation of Bill Clinton’s mother’s travels and the Pentagon’s unauthorized release of Perot’s Navy fitness reports as examples.

Perot’s fears about his and his family’s personal safety date back to 1969, when, he has said, the North Vietnamese hired Black Panthers to assassinate him for his role in trying to improve conditions for American POWs held by Hanoi.

Perot mentioned the supposed assassination plot during the third presidential debate on Oct. 19, when he said that “the most significant effort they had one night is five people coming across my front yard with rifles.”

Perot said earlier this year in a television interview that the Black Panther plot had been uncovered by the FBI, which had infiltrated the radical group and warned him of his danger.

But FBI officials contacted by The Times this spring said they had never heard of such an incident, and an extensive ABC News investigation could find no evidence of armed intruders at Perot’s North Dallas home.

The ABC report quoted Paul McCaghren, who directed Dallas police intelligence operations in 1969, as saying that no such attack could have taken place without law enforcement hearing about it. “Listen to me,” he said. “It didn’t happen. It did not happen.”

Perot’s penchant for security can be seen at his home, which is surrounded by a 10-foot-high brick wall and is under constant video surveillance and 24-hour guard. The only access is through a solid wrought-iron driveway gate controlled from a security station within the compound walls.

Perot’s business, Perot Systems, is headquartered in a North Dallas skyscraper, but the company name does not appear on the building’s ground-floor directory and the offices are secluded behind mirrored doors. Even his campaign offices have elaborate security systems, requiring the use of coded cards to open a series of doors before reaching the inner sanctum where Perot’s aides labor.

Perot has been accused of investigating his employees, business rivals and political foes, but he denies he has done so on a large scale.

As recently as this summer, his campaign spent more than $60,000 to hire private investigators to look into the backgrounds of volunteers in his petition-gathering operation. Perot said he was unaware of the probe until afterward, but that he was required by federal election law to investigate reports that money was being skimmed from the campaign and that some of the volunteers might have criminal backgrounds. His campaign hired a San Francisco detective agency to conduct the checks.

The Federal Trade Commission said earlier this month that it had received a number of complaints about potentially illegal credit checks of Perot volunteers conducted at the request of the Perot campaign.

FTC officials said that the agency had turned over its evidence of possible violations of privacy and credit reporting laws to the FBI.