convicted on ... charges• But in 1998 those prisons held 236,800 people convicted on drug charges-57 percent more than had been there in 1990.• Officials said he had been at San Quentin since June of this year after being convicted on murder charges.• The men, convicted on espionage charges, had been sentenced to 15-year prison terms in 1987.• Jim GuyTucker, were convicted on related fraud charges last May.