A man who said he planned and conducted two dozen assassinations and kidnapings, testified yesterday that the Uzi submachine gun a former State Department officer is charged with smuggling out of the country last year was inappropriate for the kind of terrorist plot the official supposedly was plotting.

The testimony came on the second day of the trial in Alexandria U.S. District Court of Walter Reed Martindale III, a former official of the Agency for International Development, who is charged with conspiracy to commit murder and gun smuggling in connection with an alleged plot to kill a flamboyant Saudi sheik.

Martindale, a Fairfax County resident, was arrested in London a year ago and convicted of bringing a semiautomatic Uzi into that country. Federal prosecutors have alleged that the gun was for use in a plot to kill Mohammed Fassi, a member of the Saudi royal family.

Assistant U.S. Attorney Justin Williams rested the government's case against Martindale late yesterday afternoon, after putting on the stand a retired Army colonel who said he purchased the gun for Martindale ostensibly as a gift for an Arab business associate.

Bruce Richard Sleagle, an ex-marine and Army weapons specialist, testified for the defense that the Uzi submachine is generally considered a collector's item rather than a terrorist weapon.

"As a professional speaking, it just has no real use in an assassination," Sleagle said. Sleagle, who said he had planned and conducted assassinations and kidnapings in what is now called Zimbabwe, testified that he had last worked as a bodyguard at the Republican National Convention for television evangelist Jerry Falwell.

Defense attorneys have maintained that Martindale traveled to London last year to work on a major business proposal to provide security for rich Arabs.

When he arrived in London, Martindale believed he was delivering a package containing radios, according to his attorneys. The package, which Martindale said was given to him by an Arab associate, was later found to contain the submachine gun, a revolver and ammunition.

After two days of testimony it was still unclear yesterday who the Arab associate was who gave Martindale the package.

Martindale is expected to take the stand today and defense attorney Paul Kramer said his client is not likely to shed much more light on the subject. "He's not sure who he is either," Kramer said during a break in the trial yesterday.

Other prosecution witnesses testified yesterday that Martindale used his diplomatic passport while traveling in London although he was no longer a government official, and that his Washington-based company, the American International Trade Group, was in financial trouble.

According to his indictment, Martindale was promised more business for his company and $50,000 for carrying out the alleged plot by Ibrahim Al-Rawaf, his partner in the Washington firm. Rawaf, who also was indicted in the case, is a fugitive.

If convicted in the trial, Martindale faces a maximum penalty of 50 years in prison and a $36,000 fine.