The executioner kept good notes.
The 16th-century parchment diary _ complete with sketches of hangings, beheadings and floggings in the margins _ recounts the grim punishments for crimes as visceral as murder and as ephemeral as witchcraft.
And if words and pictures aren't chilling enough, there is always the real thing: iron masks that were once clamped on slanderers, a chamber of metal spikes or a body cage where the only way to come out is as a skeleton.
"This is not just a house of horrors, it serves as a testament to crime and the response to it through the ages," said Nicola Coco, scientific consultant to Rome's Museum of Criminology.
The collection _ one of the world's best storehouses of torture implements and records _ was opened to the public last week after being used exclusively for students and researchers for more than 60 years.
The exhibits have already drawn thousands of visitors _ some of whom are driven to make an early exit.
"Enough," said Laura Lumino, who accompanied her two teenage sons. "I don't know how they can enjoy it."
The ancient Romans did not invent torture, but they certainly refined it. The exhibits start with models of such objects as a bronze bull, where subjects would be stuffed inside and cooked alive over an open fire.
To obtain a confession, suspects could be forced to straddle atop a wooden pyramid and then be covered with heavy weights.
The Middle Ages and the Inquisition yielded new ways to bring anguish: pouring hot oil into the ears of suspected witches; being lashed to horses which then gallop in opposite directions; getting strapped to a wheel and raked over barbs; and being impaled inside the "Virgin of Nuremberg," a spike-filled metal chamber favored by 16th century German courts.
The Enlightenment brought other methods. Some devices _ such as the guillotine and the hanging cage, where suspects would be left to starve _ were used in Europe until early this century, before electric chairs and lethal injections. The cage was last used in Sicily in 1928.
"Torture and executions are not just the domain of some dark past," said the museum's director, Claudia Greco.
"This museum is about cruelty and ignorance," she said. "It seems there is always a lot of this around."