GAINESVILLE — Attorneys for two remaining defendants in an alleged Georgia-based plot to attack government targets demanded more details Tuesday about the evidence federal agents have gathered against them, as the two men appear headed for trial.

Lawyers representing Ray Adams, 55, and Samuel Crump, 68, gave no indication at Tuesday’s federal court hearing whether they would seek a plea deal weeks after the two other men charged in the plot pleaded guilty to weapons charges and agreed to cooperate with prosecutors. Adams and Crump are charged with conspiring and attempting to make a biological toxin called ricin.

Adams’ attorney, Barry Lombardo, said “no, no, no” when asked if his client is pursuing a plea deal. Crump’s lawyer, Dan Summer, declined to comment, which has been his typical response to questions about the charges.

The defense attorneys worked Tuesday to lay the groundwork for the trial, prodding prosecutors to release more details about how the government intends to prove that the two men tried to use ricin as a weapon. They also wanted more details about the type of surveillance equipment used by an undercover informant who recorded dozens of hours of conversations in which the men talked about their anti-government views and what kinds of attacks they could plot.

Their defense likely grew more difficult last month when Frederick Thomas, the group’s suspected ringleader, and Dan Roberts pleaded guilty to conspiring to get an unregistered explosive and an illegal gun silencer. Thomas, 73, and Roberts, 67, could face up to five years in prison and a 250,000 fine.

“We’re going to need lots of investigative time and perhaps lots of investigators,” Summer said during the hearing. “Thomas and Roberts are obviously cooperating with prosecutors. We’re at an extreme disadvantage so as much information as we can have will help us prepare for the case.”

In the tapes, the four allegedly boasted of a list of government officials who needed to be “taken out” by them; talked about scattering ricin from a car speeding down a highway past major U.S. cities; and scouted tax offices.

At one point, Thomas said, “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, killing 168 people.

The four were arrested in early November after at least seven months of surveillance by an undercover informant who infiltrated their meetings at homes, during car rides and a Waffle House restaurant.

Testimony and court documents show the men played distinct roles in the suspected plot. While Thomas and Roberts were both described as early members of the scheme who brought Crump and Adams into the mix after Roberts talked of obtaining ricin, which he called a “silent killer” that can be lethal in small doses.