Cáceres was shot dead a year ago while supposedly under state protection after receiving death threats over her opposition to a hydroelectric dam.
The murder of Cáceres, winner of the prestigious Goldman environmental prize in 2015, prompted international outcry and calls for the US to revoke military aid to Honduras, a key ally in its war on drugs.
Eight men have been arrested in connection with the murder, including one serving and two retired military officers.
Officials have denied state involvement in the activist’s murder, and downplayed the arrest of the serving officer Maj Mariano Díaz, who was hurriedly discharged from the army.
But the detainees’ military records and court documents seen by the Guardian reveal that:
Díaz, a decorated special forces veteran, was appointed chief of army intelligence in 2015, and at the time of the murder was on track for promotion to lieutenant colonel.
Another suspect, Lt Douglas Giovanny Bustillo joined the military on the same day as Díaz; they served together and prosecutors say they remained in contact after Bustillo retired in 2008.
Díaz and Bustillo both received military training in the US.
A third suspect, Sgt Henry Javier Hernández, was a former special forces sniper, who had worked under the direct command of Díaz. Prosecutors believe he may also have worked as an informant for military intelligence after leaving the army in 2013.
Court documents also include the records of mobile phone messages which prosecutors believe contain coded references to the murder.
Bustillo and Hernández visited the town of La Esperanza, where Cáceres lived, several times in the weeks before her death, according to phone records and Hernández’s testimony.
A legal source close to the investigation told the Guardian: “The murder of Berta Cáceres has all the characteristics of a well-planned operation designed by military intelligence, where it is absolutely normal to contract civilians as assassins.
“It’s inconceivable that someone with her high profile, whose campaign had made her a problem for the state, could be murdered without at least implicit authorisation of military high command.”
The Honduran defence ministry ignored repeated requests from the Guardian for comment, but the head of the armed forces recently denied that military deaths squads were operating in the country.
Five civilians with no known military record have also been arrested. They include Sergio Rodríguez, a manager for the internationally funded Agua Zarca hydroelectric dam which Cáceres had opposed.
The project is being led by Desarrollos Energéticos SA, (Desa), which has extensive military and government links. The company’s president, Roberto David Castillo Mejía, is a former military intelligence officer, and its secretary, Roberto Pacheco Reyes, is a former justice minister. Desa employed former lieutenant Bustillo as head of security between 2013 and 2015.
Cáceres had reported 33 death threats linked to her campaign against the dam, including several from Desa employees. Desa denies any involvement in the murder.
Cáceres was killed at about 11.30pm on 2 March, when at least four assassins entered the gated community to which she had recently moved on the outskirts of La Esperanza.
A checkpoint at the entrance to the town – normally manned by police officers or soldiers – was left unattended on the night she was killed, witnesses have told the Guardian.
Initially, investigators suggested the murderer was a former lover or disgruntled co-worker. But amid mounting international condemnation, Díaz, Bustillo and two others were arrested in May 2016.
Hernández, who was eventually arrested in Mexico, is the only suspect to have given detailed testimony in court. He has admitted his involvement, but says he acted under duress.
All eight have been charged with murder and attempted murder. The other seven suspects have either denied involvement or not given testimony in court.
Prosecutors say that phone records submitted to court show extensive communication between the three military men, including a text message which was a coded discussion of payment for a contract killing.
American experts have been involved in the investigation from the start, according to the US embassy in Tegucigalpa.
Senator Ben Cardin, ranking member of the Senate foreign relations committee, said US support should not be unconditional: “It is essential that we not only strengthen our commitment to improving the rule of law in Honduras, but we must also demand greater accountability for human rights violations and attacks against civil society.”
Last year, the Guardian reported that a former Honduran soldier said he had seen Cáceres’s name on a hitlist that was passed to US-trained units.
1Sgt Rodrigo Cruz said that two elite units were given lists featuring the names and photographs of activists – and ordered to eliminate each target.
Cruz’s unit commander deserted rather than comply with the order. The rest of the unit were then sent on leave.
In a follow-up interview with the Guardian, Cruz said the hitlist was given by the Honduran military joint chiefs of staff to the commander of the Xatruch multi-agency taskforce, to which his unit belonged.
Cruz – who asked to be referred to by a pseudonym for fear of retribution – deserted after Cáceres’s murder and remains in hiding. The whereabouts of his former colleagues is unknown.
Following the Guardian’s report, James Nealon, the US ambassador to Honduras, pledged to investigate the allegations, and in an interview last week, said that no stone had been left unturned.
“I’ve spoken to everyone I can think of to speak to, as have members of my team, and no one can produce such a hitlist,” said Nealon.
But the embassy did not speak to the Xatruch commander, Nealon said. Activists, including those with information about the alleged hitlist, have told the Guardian they have not been interviewed by US or Honduran officials.
Lauren Carasik, clinical professor of law at Western New England University, said America’s unwavering support for Honduras suggests it tolerates impunity for intellectual authors of high-profile targeted killings.
“Washington cannot, in good conscience, continue to ignore mounting evidence that the Honduran military was complicit in the extrajudicial assassination of Cáceres.”
Extrajudicial killings by the security forces and widespread impunity are among the most serious human rights violations in Honduras, according to the US state department.
Nevertheless, the US is the main provider of military and police support to Honduras, and last year approved $18m of aid.
In recent years, US support has focused on Honduras’s special forces units, originally created as a counterinsurgency force during the 1980s “dirty war”.
The elite units ostensibly target terrorism, organised crime and gangs, but campaigners say the Honduran intelligence apparatus is used to target troublesome community leaders.
Violence against social activists has surged since a military backed coup d’état ousted populist president Manuel Zelaya in 2009. Since then at least 124 land and environmental campaigners have been killed.
A recent investigation by corruption watchdog Global Witness described extensive involvement of political, business and military elites in environmentally destructive mega projects which have flourished since the coup.
One of the most troubled parts of the country has been northern Bajo Aguán region, where a land conflict between palm oil companies and peasant farmers has claimed more than 130 lives over the past six years.
The Bajo Aguán is also home to the 15th battalion – one of two special forces units in the Honduran army – and the special forces training centre.
Two of the suspects, Díaz and Hernández, served in the 15th battalion together; Cruz’s elite unit was also stationed in the Bajo Aguán.
Ambassador Nealon said that there was no record of Díaz, Hernández or Bustillo attending any US training courses in Honduras.
“Our training programmes for police or for military are not designed to instruct people in how to commit human rights violations or to create an atmosphere in which they believe that they are empowered to commit human rights violations, in fact, just the opposite,” said Nealon.
Honduran military records show that Díaz attended several counterinsurgency courses at special forces bases in Tegucigalpa and in the Bajo Aguán.
He also attended cadet leadership courses at Fort Benning, Georgia, in 1997, and a counter-terrorism course at the Inter American air force academy in 2005.
The court documents also reveal that at the time of his arrest, Díaz, 44, was under investigation for drug trafficking and kidnapping, while also studying for promotion.
Military records show that in 1997, Bustillo attended logistics and artillery courses at the School of the Americas, at Fort Benning, Georgia, which trained hundreds of Latin American officers who later committed human rights abuses.
Author: Nina Lakhani