Tightened security surrounds Reagan as he resumes full schedule

President Reagan this week returned to full-time work and a beefed up protection program. Following the assassination attempt two months ago, much stricter crowd control, evasive travel patterns, less publicized scheduling, and the occasional wearing of a bulletproof vest all are part of the President's new security regimen.

Informal press access to Mr. Reagan -- those occasions when the President stops to field impromptu questions when traveling from one location to another -- have been sharply curtailed. It was in such a situation that the President was shot, and security experts call these the most likely times for an assailant to strike.

At the same time, the administration is reconsidering its earlier decision to cut back on the federal program to keep track of gun sales, officials say. It was this program, run by the Treasury Department's Bureau of Alcohol, Tobacco, and Firearms, that enabled federal officials to trace the pistol used in the Reagan assassination attempt in just 16 minutes.

As has been the case in the past, the March 30 attack on the President was followed by a sharp increase in threats."It was quite hectic for the first few weeks," says Secret Service special agent Laurie Davis.

Both the White House and the Secret Service are typically closemouthed about specific changes in presidential protective measures.

But many changes are obvious to those who follow the President's activities. "Decoy" vehicles have been used when Mr. and Mrs. Reagan travel by auto. Secret Service sharpshooters were observed near the President when he addressed West Point cadets last week. Those close to Mr. Reagan say he wants to continue mingling with the public, but he probably will follow more closely the advice of Secret Service officials who have been urging greater caution.

"There have been no major changes taken since the assassination attempt," a Secret Service spokesman says. But an official with the Treasury Department (which oversees the Secret Service) says, "I'm sure there will be some changes. . . . There has to be."

While the President has not heeded the advice of his good friend comedian Bob Hope and embraced gun control, the White House is expected to revise its thinking on an important means of keeping track of weapons.

The administration had intended to drastically reduce the number of Treasury Department officers who randomly inspect the records of gun dealers. Law enforcement officials say this practice helps weed out illegal dealers and makes it easier to track down criminals who use guns.

The Bureau of Alcohol, Tobacco, and Firearms had been preparing for a "reduction in force" in the gun-tracing program. But since the attempt on Mr. Reagan's life, according to a Treasury Department official, there will be "a reversal in the cutback of ATF personnel."

The Treasury Department's probe of the Secret Service handling of the assassination attempt should be completed by the end of June. A US House subcommittee that oversees the Secret Service plans to meet next week with its officials.

"We went to get a handle on what the Secret Service does to evaluate its systems for protecting the President," said subcommittee staff member Peter Barash. "We are interested in knowing the extent to which the Secret Service uses outside audits, analyses, and studies ." Hearings may follow.