What criminal act did banneker accuse thomas jefferson of, even though jefferson hated it in the english?

Benjamin Banneker accused Thomas Jefferson of being tyrannical to his slaves.  The term tyranny was something Jefferson also hated from what the British had done to the colonies during his rule.  Though he told his overseers not hurt the slaves, many nonetheless were whipped as his orders were ignored.

11-12 weeks.       (random sentence to make this 20 characters long).