From: Star Trek: The Next Generation
An android, of the same model and appearance as Lt. Commander Data of the U.S.S. Enterprise-D. Created, as was Data, by Doctors Noonien and Juliana Soong on Omicron Theta, Lore's emotional functions were more like organic creatures (thanks to an emotion chip developed by the Soongs), though completely malevolent and self-serving, with no regard for life.
He was responsible for the death of all colonists on Omicron Theta and proved exceptionally dangerous during several encounters with his "brother" Data and the crew of the Enterprise. He met his ultimate fate while attempting to lead a rogue Borg faction, when a group of them rebelled against him. After deactivation and dismantling, his emotion chip was salvaged from his body.