TAMPA, Fla. (AP) _ Explosives, silencers and hollowed-out ammunition were found in the home of the owner of an investment company and her son, who are charged with plotting to kill a judge who shut down their business, federal agents testified Monday.

Janice Weeks-Katona, founder of Premier Benefit Capital Trust, and her son Jason Spencer Weeks, the company's portfolio manager, were ordered held without bond after Monday's three-hour hearing before U.S. Magistrate Thomas Wilson. They are charged with conspiracy to commit murder and conspiracy to commit mail fraud.

An informant told investigators the pair schemed to kill U.S. District Judge Steven Merryday and five others, including regulators and a court- ordered receiver who ''conspired to take their company from them,'' according to an FBI affidavit. There was no mention of any attempt to carry through with the plans.

The informant, who lived with Weeks-Katonah and her son for six months, said they wanted to annihilate their enemies and used the words ''murder and kill,'' FBI agent Robert E. Carroll said.

The mother and son were taken into custody in mid-March.

Investigators found four unlicensed homemade silencers, two 3 3/4 -inch long homemade explosives and hollowed-out, .22-caliber bullets inside their home, said Joseph Magro of the federal Bureau of Alcohol, Tobacco and Firearms.

In July, Merryday ordered Premier shut down and its assets frozen after the Securities and Exchange Commission accused the company of lying about the safety of its high-yield ''investment certificates.''

The company mailed out brochures promising a 12 percent return in nine months, interest four times higher than what banks offered, said John Michael Brown, a state comptroller's investigator.

The company ignored an injunction and a cease and desist order and kept doing business in 28 states, said another investigator, John Michael Brown.

Merryday appointed a receiver to take over Premier's accounts and pay back investors. He turned the case over to another judge in January, and has said he was aware of the threat against him.

According to the affidavit, the other murder targets were Tampa attorney Charles Stutts, the court-appointed receiver; Martha Cook, the attorney for the receiver; Mike Brown and Ray Lemme, investigators with the State Comptroller's Office; and Greg Little, an attorney with the SEC.