Updated

Four suspected members of a Georgia militia charged with plotting attacks with toxins and explosives against government officials pleaded not guilty Wednesday to federal charges.

The four men entered their pleas at a bond hearing at a federal courthouse in north Georgia. Prosecutors say the men talked of assassinating U.S. Attorney General and former U.S. Rep. Cynthia McKinney, as well as other officials. The men had stockpiled 52 guns and 30,000 rounds of ammunition, including bullets meant for sniper rifles at the home of Frederick Thomas, prosecutors said.

Prosecutors have accused the 73-year-old Thomas and 67-year-old Dan Roberts of conspiring to obtain an explosive and possessing an unregistered silencer. Authorities also charged 55-year-old Ray Adams and 68-year-old Samuel Crump with conspiring and attempting to make ricin, a biological toxin that can be lethal in small doses. If convicted, they could face more than a decade in prison.

Defense attorneys argued that the four men are too old and infirm to carry out such ambitious attacks. Thomas is a great-grandfather and suffers from a host of illnesses, including back pain, heart disease and emphysema, said lawyer Jeff Ertel.

Thomas' wife of 51 years, Charlotte, testified that her husband, a Navy veteran, would never harm the government.

"He loves his country," she said. "He's the most patriotic man I've ever met."

Prosecutors dismissed claims that the men are too old to have executed the alleged plot.

"Age is not a barrier to the crimes these defendants are charged with," prosecutor Robert McBurney said. The men, he told the judge, "can pull a trigger just as easily as you or I can."

The four allegedly boasted of a "bucket list" of government officials who needed to be "taken out"; talked about scattering ricin from a plane or a car speeding down a highway past major U.S. cities; and scouted IRS and ATF offices, with one man saying, "We'd have to blow the whole building like Timothy McVeigh," a reference to the man executed for bombing a federal building in Oklahoma City in 1995.

Federal investigators said they had them under surveillance for at least seven months, infiltrating their meetings at a Waffle House, homes and other places, before finally arresting them last week. The arrests came just days after authorities say they discovered evidence they were trying to extract ricin from castor beans.