After winning a prestigious international prize for her environmental activism last year, she said indigenous leaders like her were frequent targets. And often, she said, her country's government was to blame.

"In my organization alone," she told CNN en Español, "we have 10 people who've been killed with total impunity."

Nearly 10 months later, investigators found Cáceres shot dead inside the home where she lived in La Esperanza, Honduras, about 110 miles west of the country's capital of Tegucigalpa.

The high-profile killing of one of the country's most well-known activists drew swift condemnation from government officials.

"The state of Honduras has been directly attacked by the death of Berta Cáceres," President Juan Orlando Hernández said in a national address. "This is a crime against Honduras, a blow to the Honduran people. It will not go unpunished."

But even as authorities vowed to investigate and apprehend whoever is responsible, activists pointed to the killing as a troubling sign that officials haven't done enough.

"That same state of Honduras took measures to persecute Bertha Cáceres for her struggle against foreign companies that destroy natural resources," the group said.

Campaign against dams drew praise, threats

A member of the Lenca indigenous group and co-founder of the Council of Indigenous Peoples of Honduras , Cáceres led a successful campaign against one of Central America's biggest hydropower projects, the Agua Zarca cascade of four giant dams in the Gualcarque River basin.

Rallying indigenous communities and international organizations, Cáceres pressured Sinohydro, the Chinese state-owned dam developer, and the World Bank's private sector arm, the International Finance Corporation, to drop out of the project in 2013.

Before she was killed, Cáceres had long been subject to repeated threats and harassment. And she wasn't alone. Tomás García, the co-founder of the council, was shot and killed during a peaceful protest against the dam in 2013.

Cáceres knew the risks she was taking, her family told CNN.

"Yes, she feared for her life. Well, in reality, she wasn't afraid, she knew that something could happen," cousin Gracia Flores said. "But that didn't make her abandon her fight."

Silvio Carrillo, her nephew, said he hoped his aunt's powerful words will now have an even wider reach.

"Her murder is an act of cowardice that will only amplify Bertita's message to bring about change in Honduras and make this a better, more humane world," he said.

Tragedy 'waiting to happen'

In her interview with CNN en Español last year, Cáceres was quick to point out that when indigenous leaders and environmentalists are killed, it shouldn't be mistaken for generalized violence.

"This is a policy of the Honduran state of criminalization. You can find it in the laws that have been approved. ... They have criminalized the human right to defend the common good and the environment, giving an incredible privilege to transnational companies that operate with tremendous impunity in Honduras," she said.

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Last year, Cáceres won the Goldman Environmental Prize for her efforts.

"She was a fearless environmental hero," said John Goldman, who heads the foundation that awards the prize . "She understood the risks that came with her work, but continued to lead her community with amazing strength and conviction."

Those who knew her work said they were devastated by her death.

"The cowardly killing of Berta is a tragedy that was waiting to happen. For years, she had been the victim of a sustained campaign of harassment and threats to stop her from defending the rights of indigenous communities," said Erika Guevara-Rosas , Americas Director at Amnesty International.

One arrested as investigation continues

Cáceres had been under guard at the time of the killing, Honduran Security Minister Julián Pacheco told CNN en Español

At least one arrest has been made in the case, he said. Another person was found injured inside the home where the attack occurred, he said. That person is under witness protection, he said, and could play a key role in solving the crime.

"Those responsible must be investigated and brought to justice," the Honduran President said on Twitter on Thursday. "We demand it."