The cold-blooded killing of a mother bear known as Amarena has angered animal rights groups and local politicians in Italy.
The brown bear was shot by a local resident of San Benedetto dei Marsi just outside the national park of Abruzzo in central Italy, the park confirmed on Friday.
Her 4-year-old cub Juan Carrito made international headlines in 2021 when he broke into a local bakery and devoured hundreds of biscuits.
"The park veterinarian intervened on the spot with the emergency team, who however could only ascertain the death of the bear given the seriousness of the wound," the park said on its Facebook page.
Amerana was a Marsican brown bear, an endangered species in Italy where fewer than 60 of the bears are still alive. Her killing is being investigated as a serious crime.
The 56-year-old man who shot her was turned over to the local police.
"The episode is very serious and causes enormous damage to the population of about 60 specimens, affecting one of the most prolific females in the history of the park," the national park statement said.
"Obviously there are no reasons to justify the episode given that Amarena had never created any type of problem for the man," it added.
The prosecutor's office in Avezzano, led by Maurizio Maria Cerrato, has opened an investigation into the killing which is against the 544bis penal code, relating to the cruel murder of an animal without warrant, the prosecutor's office told CNN.
If convicted the man in question could face from four months to two years in prison.
The man told police he had shot the animal "out of fear, but I didn't want to kill it, I found it inside my property. It was an impulsive, instinctive act," according to CNN affiliate Sky24.
Amerana's famous biscuit-stealing cub Juan Carrito died earlier this year after being hit by a car. Her current young cubs were found following a search late Thursday. They are being cared for by park authorities.
Italy's environment minister Gilberto Pichetto called the killing a "serious" matter.
"It is necessary to clarify as soon as possible. I am in constant contact with all the institutional actors who are working to shed light on the matter: maximum coordination is now needed between the ministry, the regions, the Park Authority, Ispra, Cufa, mayors and prefects. Our commitment is also aimed at protecting the bear cubs, doing everything so that they can remain in freedom."
Of the 15 bears that have been killed in Italy since 2010, three have been killed in Abruzzo.
In April, a 17-year-old bear that killed a 26-year-old jogger was sentenced to death in the northern region of Trento. The bear was given a stay of execution and has been captured.