The Teardrop massacre occurred in 0.5 ABY. An entire town was devastated by Imperial stormtroopers.
The Galactic Empire suspected a Rebel Alliance cell of being on the planet Teardrop, and the Star Destroyer Reprisal had been ordered to destroy the Rebel ships with no mercy.
By the time the ship had arrived there, the Rebels had already evacuated. The last of the ships to leave Teardrop before the Imperials landed was the Millennium Falcon. The transport was carrying the last of the technicians and equipment needing evacuation from the planet. The crew included Luke Skywalker, Han Solo, and Chewbacca.
The Reprisal.
The Millennium Falcon was leaving the planet when it was attacked by Pirate starfighters. Solo and Skywalker managed to destroy a large amount but they were surpassed by the number. Ironically, they were eventually rescued by the turbolasers of the Reprisal. Expecting to find Rebels fleeing Teardrop, Captain Kendal Ozzel was tricked by Solo who presented the Millennium Falcon as a civilian ship and insisted to access the planet. Ozzel ordered him to leave the planet and the Rebels immediately did it.
The ship's ISB officer, Major Drelfin, ordered stormtroopers into a town and had them fire on civilians, with aliens first, with the intent of blaming it on Rebel agitators within the town's populace. Stormtroopers like Daric LaRone were split up into groups and sent into the city. Stormtrooper snipers such as Taxtro Grave were assigned to rooftop duty.
This massacre resulted in the casualties of an entire town full of unarmed civilians.
As a result of the massacre, stormtrooper Daric LaRone later killed Major Drelfin on the Reprisal. He escaped the ship in a stolen ISB transport along with four other stormtroopers: the future Hand of Judgment.