BOLZANO, Italy — When the head of a small Italian museum called Detective Inspector Alexander Horn of the Munich Police, she asked him if he investigated cold cases.

“Yes I do,” Inspector Horn said, recalling their conversation.

“Well, I have the coldest case of all for you,” said Angelika Fleckinger, director of the South Tyrol Museum of Archaeology, in Bolzano, Italy.

The unknown victim, nicknamed Ötzi, has literally been in cold storage in her museum for a quarter-century. Often called the Iceman, he is the world’s most perfectly preserved mummy, a Copper Age fellow who had been frozen inside a glacier along the northern Italian border with Austria until warming global temperatures melted the ice and two hikers discovered him in 1991.

The cause of death remained uncertain until 10 years later, when an X-ray of the mummy pointed to foul play in the form of a flint arrowhead embedded in his back, just under his shoulder. But now, armed with a wealth of new scientific information that researchers have compiled, Inspector Horn has managed to piece together a remarkably detailed picture of what befell the Iceman on that fateful day around 3300 B.C., near the crest of the Ötztal Alps.