Midday on Friday, March 2, as family and colleagues marked the second anniversary of the murder of Berta Cáceres, Honduran federal police arrested Roberto David Castillo Mejía at the San Pedro Sula international airport as he tried to leave the country.

Honduran authorities are charging Castillo Mejía with being an “intellectual author” of Cáceres’s assassination. “Castillo was in charge of providing logistical support and other resources to one of the material authors,” authorities said in a press release.

Berta Cáceres, a renowned Honduran environmentalist, feminist, and indigenous leader, was murdered in her home just before midnight on March 2, 2016, provoking widespread outrage in Honduras and across the world.

Gustavo Castro, a Mexican activist and close friend of Cáceres’s who had gone to her house that night to prepare for a workshop the following day, miraculously survived a close-range shot to the head. "When I saw in [the gunman’s] eyes the decision to kill me, I instinctively moved my hand and head," Castro told me in an interview in Mexico City in 2016 during the course of investigating Cáceres’s murder for Sierra. "The killer experienced an optical illusion that he had shot me in the head.”

Castillo Mejía’s arrest is the ninth so far in the case. Previous arrests have included former and active military agents as well as mid-level executives from Desarrollos Energéticos, or DESA, the company behind the Agua Zarca dam that Cáceres and her organization, the Civic Council of Popular and Indigenous Organizations of Honduras (COPINH), fought against.

Castillo Mejía graduated from West Point in 2004 and served in the Intelligence and Counter-Intelligence Department of the Honduran Armed Forces. In 2008, Castillo Mejía began working for the Honduran National Electric Energy Company while still on active duty with the Honduran Armed Forces. This led Castillo Mejía to come under investigation for corruption, as in Honduras it is illegal to take two distinct federal salaries at the same time.

Castillo Mejía became the executive president of DESA in 2011, a position he maintained during the years of conflict with COPINH and at the time of Cáceres’s murder.

I heard the name David Castillo Mejía repeatedly when I reported on Cáceres’s murder in Honduras at this time last year.

Brigitte Gynther, who has worked in Honduras with the School of the Americas Watch since 2012 and often accompanied Berta Cáceres on her trips to Rio Blanco to coordinate anti-dam protests, told me that Castillo Mejía constantly harassed Cáceres. “David Castillo called Berta a lot. And he wouldn’t call to threaten her, but he would know things about her,” Gynther said. She cited as an example one time when Cáceres was preparing to travel to Cuba for a school graduation ceremony for one of her daughters. A few days before the trip, Castillo called Cáceres (with Gynther there in her presence) and said, “We’re going to let you leave the country to go to Bertita’s graduation before the prohibition kicks in.”

“She would always get these calls from him,” Gynther told me last year. “He worked in military intelligence.”

Rosalina Dominguez Madrid was one of Cáceres’s closest companions in the struggle against DESA’s proposed dam in Rio Blanco. When I spoke with her at COPINH’s headquarters last year, she told me that she heard David Castillo Mejía repeatedly try to offer Cáceres money to negotiate. “Why did they kill Berta? Because she never sold out,” Dominguez said.

Salvador Zúñiga, Cáceres’s ex-husband and co-founder of COPINH, said that Cáceres told him of repeated harassment from Castillo Mejía. “She told me clearly that David Castillo, who was the president of DESA’s board of directors, was going to have her killed,” Zúñiga told me last year.

My repeated attempts in 2017 to reach Castillo Mejía and other DESA executives by email and telephone were unsuccessful.

DESA released a statement last week claiming, “David Castillo, like all members of DESA are (sic) completely unrelated to the unfortunate event that terminated the life of Ms. Berta Cáceres.”

COPINH also released a statement on March 2, saying, “David Castillo is only one piece” of the “the entire murderous, criminal structure behind the assassination of our sister Berta Cáceres.”

COPINH has adamantly called for the entire DESA board of directors as well as several high level federal officials to be investigated for their possible participation in ordering, planning, and paying for Cáceres’s murder.

In November 2017, an independent panel of experts released a report arguing that Cáceres’s murder was “not an isolated event” but “the culmination of a series of aggressions against her” in which DESA executives and high-level state authorities participated.

Victor Fernández, both a colleague of Cáceres’s and the family’s lawyer, said in a video statement: “We learned that Mr. David Castillo was recently captured. The family and COPINH have been calling for his capture for a long time, since he clearly participated in the crime. He was the person who constantly called and had encounters with Berta. His capture is good news. But let us hope that his capture, especially on this very day [the second anniversary of Cáceres’s murder], does not correspond to some kind of manipulation on behalf of the federal authorities.”

Castillo Mejía’s arrest comes after both increased scrutiny of the Cáceres murder and some three months of political turmoil in the country.

In late November and early December 2017, hundreds of thousand of Hondurans took to the streets to denounce alleged electoral fraud in the November 26 presidential elections.

The Honduran electoral conflict itself stems from a bitter irony: The perpetrators of the 2009 military coup justified overthrowing then-president Mel Zelaya because, they claimed, he planned to change the Honduran constitution to allow for presidential reelection. Juan Orlando Hernández supported the coup, later became president and then promptly changed the constitution so that he could run for reelection.

When Hernández appeared to be losing in the first vote counts, all reports of the vote count were inexplicably interrupted for some 30 hours, provoking widespread protest and outcry.

On December 17, the Honduran Electoral Tribunal declared Hernández the winner with a 1.53 percent margin. After weeks of protest, security forces began to arrest activists at roadblocks and in their homes. Edwin Espinal, a long-standing Honduran activist who organized against the coup in 2009, has been in jail some 50 days.

Fernández, in his statement posted online, emphasized the need to honor Berta Cáceres and do justice for her by organizing against “the extractive model” and continuing the struggles to which Cáceres was so dedicated.

“That is one of the most important ways we can do justice,” he said, “to continue the fight for justice ourselves in the social sphere.”

An initial hearing in the case against Castillo Mejía is scheduled for March 9.