Topeka ? Two California men found guilty of drug trafficking in what has been called the largest seizure by federal drug agents of an operable LSD lab must wait until Monday to find out how much time they will spend in prison.

In March, William Leonard Pickard, 57, and Clyde Apperson, 47, both of the San Francisco area, were found guilty of conspiracy to manufacture and distribute more than 10 grams of LSD and possession with intent to distribute the illegal drug. Each faces 10 years to life imprisonment.

The sentencing hearing began Thursday before U.S. District Judge Richard Rogers, with defense attorneys spending much of the day challenging the amount of drugs the government said was taken three years ago from a former missile silo near Wamego.

Both defendants entered the courtroom wearing leg shackles and orange prison suits. Pickard’s attorney, Billy Rork, questioned Drug Enforcement Administration chemist Timothy McKibben in minute detail about numerous lab worksheets and reports.

And Apperson’s attorney, Mark Bennett, told the court, “The issue is whether the calculations were properly made.”

At the end of the day, the judge made clear his intent: “We’ll complete the sentencing in this case next Monday.”

During an 11-week trial that started in January, testimony indicated the DEA seized about 90 pounds of material containing LSD, another 214 1/2 pounds of material with precursor lysergic acid, 52 pounds of material with byproduct iso-LSD, and nearly 43 pounds of material with precursor ergocristine.

Testimony also showed the weight was based on the number of containers found and the amount they contained.

Prosecutors said no LSD was made at the Wamego silo, about 15 miles east of Manhattan, and the material with the LSD found there came from elsewhere.

During the trial, prosecutors contended Pickard and Apperson were part of an LSD ring.

Pickard testified he was en route to destroy the LSD lab on Nov. 6, 2000, when state troopers stopped his vehicle and Apperson’s rental truck.

The truck and car contained a complete LSD laboratory. Included was about $600,000 worth of chemicals essential for LSD manufacturing.