A Worcester, Mass., man arrested here Tuesday after he allegedly threatened to kill Secretary of State George P. Shultz and President Reagan was indicted yesterday on two federal and four D.C. firearms violations.

The indictment of Edward Louis Gallo, 41, stems from the three weapons -- a sawed-off shotgun, a machine gun and a regular shotgun -- that were recovered from Gallo's car after he was arrested at the Regency Congress Inn on New York Avenue NE.

D.C. police began looking for Gallo after his mother told federal authorities in Massachusetts on Monday that her son had left home to drive to Washington, carrying three recently purchased weapons and threatening Shultz and Reagan.

Gallo's car was found at the Congress Inn, where he had registered Monday night. Police sealed off the area while they searched for the weapons, tying up morning rush-hour traffic for miles.

Gallo told police and reporters that he was a tourist in Washington and that he had planned to go hunting here.

The six counts against Gallo, an unemployed chemist, carry a maximum imprisonment of 24 years.

The indictment is apparently the first in the District to trigger the new federal sentencing guidelines, which set specific prison terms for federal offenses.

However, prosecutors were unable to say last night what prison term Gallo might face if convicted of all counts.

The unusually speedy indictment of Gallo came one day before he was to appear before U.S. Magistrate Jean F. Dwyer for a preliminary hearing to determine if there was enough evidence to refer the case to the grand jury.

Gallo's attorney, Christopher Davis, said last night that he had not received a copy of the indictment and had no comment.

The indictment charges Gallo, who lived with his mother, with interstate transportation of a sawed-off shotgun and possessing an unregistered sawed-off shotgun, both federal offenses.

D.C. police said they recovered from Gallo's car a Remington Model 820 12-gauge shotgun. The shotgun had been sawed off at the barrel and stock.

Gallo also was charged with possessing an AR15 rifle, described in the indictment as a machine gun, possessing a Mossberg shotgun and possessing ammunition.

The rifle, shotgun, 325 rounds of ammunition and three loaded magazine clips for the AR15 also were recovered from Gallo's car, police said.

The case was assigned to U.S. District Judge William B. Bryant.