Short answers, pulled from the story.
The Marzabotto massacre took place between the 29th of September and the 5th of October 1944. The heaviest killing occurred on the first two days, with approximately 550 civilians killed on the 29th of September alone.
Approximately 770 people were killed during the massacre across 115 locations. The victims included 216 children, 316 women, 142 elderly people, and five priests. The widely cited figure of 1,830 deaths refers to a broader post-war commemorative count, not to the massacre alone.
The massacre was carried out primarily by the 16th SS Panzergrenadier Division "Reichsführer-SS," especially SS Panzer Reconnaissance Battalion 16 commanded by SS-Sturmbannführer Walter Reder. Overall command of the operation rested with SS-Sturmbannführer Helmut Looß.
Several officers were convicted at different times. Walter Reder was sentenced to life imprisonment by the Military Tribunal of Bologna in 1951 and released conditionally in 1980. In 2007, the Military Tribunal of La Spezia sentenced ten defendants to life imprisonment in absentia. None of those convicted was extradited or imprisoned in Italy.
The name "Monte Sole massacre" more accurately identifies the wider mountainous area in which the killings occurred, spanning the municipalities of Marzabotto, Monzuno, and Grizzana Morandi. The name "Marzabotto massacre" became internationally widespread because of the public prominence of the municipality of Marzabotto and the memorial sites located there.
The armadio della vergogna, or "Cabinet of Shame," was a collection of files on Nazi and Fascist war crimes discovered in Rome in 1994 that had been provisionally archived and effectively hidden. Its discovery led to new investigations into several massacres, including Monte Sole, and ultimately to the 2007 trials at the Military Tribunal of La Spezia.