TEGUCIGALPA, HONDURAS -- The man convicted last year of co-ordinating the killing of Honduran environmental activist Berta Caceres was sentenced Monday to more than 22 years in prison, upsetting the victim's family because the penalty was significantly below the maximum.

A judge sentenced Roberto David Castillo Mejia to 22 years and six months in prison for the murder of Caceres, a member of the Lenca Indigenous group who led opposition to a dam project in which Castillo Mejia was involved. He will be able to appeal.

Olivia Zuniga Caceres, daughter of the activist who protested with others outside the court, said she would make every effort to seek a more severe sentence.

"It is extremely outrageous that the maximum penalty was not applied," Zuniga Caceres said, noting that the convicted gunmen received longer sentences.

In December 2019, seven men were sentenced to prison for Caceres' murder. Four men were sentenced to 34 years for the murder and 16 years for attempted murder. Three others received sentences of 30 years for their roles.

"This is the result of a justice system that has nothing to do with justice, that promotes impunity," Zuniga Caceres said, also saying she still awaited the capture of others involved in ordering her mother's killing.

At the time, prosecutors said the killers acted on behalf of a company, Desa, that was building a dam being opposed by the activist. Castillo Mejia, who heads the project, was arrested in 2018.

Castillo Mejia allegedly paid the hitmen, gave logistical support and provided resources to those already convicted, according to prosecutors.

Caceres was a co-founder of the National Council of Popular and Indigenous Organizations of Honduras. She helped organize opposition to the Agua Zarca dam, which was to be built on the Galcarque River. The river holds spiritual importance for the Lenca people as well as being a critical source of water. The dam project remains frozen.

Caceres won the prestigious Goldman Prize for her environmental activism in 2015. She was slain at her home in La Esperanza on March 3, 2016. A Mexican activist who was there with her also was shot, but survived.