Rangers were following an order by Provincial President Maurizio Fugatti to eliminate a bear considered dangerous.
The female bear, KJ1, was suspected of being involved in at least seven interactions with humans, including an attack on July 16 on a French tourist in which the victim suffered injuries to his arms and legs.
The bear was killed in the woods in the Padaro area, where it had been located via its radio collar.
The province said environmental agency Ispra had confirmed that the animal was high risk and needed to the eliminated.
“I have already told President Fugatti that the killing of individual bears is not the solution to the problem,” said Pichetto Fratin.
“I understand the state of mind of the local administrators and population, but today we are experiencing the effects of a past mistake, due to an imprudent decision to exploit the image of bears in Trentino for tourism 25 years ago.
“Certainly a way forward is sterilisation and we are working on it with Ispra.
“But this measure … risks being insufficient.”
Animal rights group Leal highlighted the plight of KJ1’s “three desperate cubs”, saying that “the orphans could fall victim to predators as they have not yet completed their path of development and self-defence”.
Bear numbers in Trentino have grown significantly following their reintroduction to the area between 1996 and 2004.
A 26-year-old trail runner was killed by a bear he accidentally ran into in Trentino last year.
The bear identified as being behind that fatal attack, JJ4, was captured and the authorities ordered it be put down, but legal action by animal rights groups prevented that.
JJ4 is set to be transferred to a reserve outside Italy.
ANSA