Testimony from three hit men working for the Guerreros Unidos drugs cartel appears to prove that the 43 missing Mexican students were killed on the night of September 26. But their families refuse to believe they are dead until they have DNA proof.
Agustín García Reyes knew exactly what he was doing as he descended the steep dirt track to the bottom of the rubbish dump in the woods.
With a group of some 30 youngsters sliding down the slope before him, into the dark hole deep in the Mexican countryside, the man nicknamedEl Chereje – which roughly translates as "The Damned Heretic" – ordered them to stop and face him.
"I asked them why they had come to Iguala, and they said they had come for the mayor's wife," García said. He ordered that their hands be tied behind their heads, and that they look not at his face, but at the ground. Then he ordered his men to shoot.
"I made them stand in the rubbish, and I said to them: 'So what do you say to this?' And then they were shot."
By the end of that evening 43 students had vanished, in an attack that has shaken Mexico to its core. And on Friday, six weeks to the day after the disappearance of the 43 trainee teachers, the Mexican government announced that it appeared to have finally solved the puzzle of what happened on the night of September 26.
"All of the federal forces are participating actively and in co-ordination in what is one of the biggest criminal investigations in living memory," said Jesus Murillo Karam, the Attorney General.
At a press conference in Mexico City he played video testimony from El Chereje and two other men working for a drugs gang who had confessed to the killings – Patricio Reyes Landa, known as El Pato or The Duck, and Jonathan Osorio Gómez, El Jona – Jonny. Their testimony, Mr Murillo said, "has allowed us to piece together the last stage of this criminal chain that we have before us." He emphasised the DNA tests had not been confirmed, but that they were confident that, at last, they had found the students.
Late on Friday night, however, the families of the disappeared refused to believe that Mr Murillo had resolved the case.
Felipe de la Cruz, speaking on behalf of the parents, said that until Mr Murillo and the authorities produced evidence of the students' deaths they would cling on to hope that they were alive.
Mr de la Cruz, whose son Yosh only survived because he was on the phone to his father at the time the students were bundled into cars, said that he would wait until the DNA results were made public.
And Julio César González, whose son is among the missing, said that he was "tired of the Attorney General giving them up for dead."
Mr Murillo admitted on Friday night that he too was tired – ending his hour-long press conference with the phrase: "No more questions. I'm tired of this."
His comments were seized upon by critics of the government's handling of the scandal, with the hashtag #YaMeCanse – I'm tired – trending on twitter, in a stream of comments such as "I'm tired of fear," "I'm tired of living in a murderous country," and "I'm tired of corruption and impunity."
The government know that, tired or not, they must bring the investigations to a swift conclusion and stem the growing wave of anger.
From the small town of Iguala in the southern state of Guerrero, where the students were abducted from, buildings were torched in fury. The demonstrations then spread to the capital. A torchlit processions of 50,000 people marched through the streets, and, hours after Mr Murillo's press conference, a candlelit vigil sprung up at the Angel of Independence statue in the centre.
And from Central America, the ripples caused by the disappearance have spread around the world – Argentine forensics have been called in to help, and bones and teeth found in mass graves are being analysed at Innsbruck University in Austria.
Enrique Peña Nieto, the Mexican president, has cut a state trip to China from ten days to seven to deal with the crisis, which is threatening to undermine all of his much-vaunted successes in capturing senior drug cartel figures.
He, like Mr Murillo, will be hoping that the testimony of the three hit men is not yet another false lead. So far 74 people have been arrested in connection with the case – among them the mayor of Iguala and his wife; their political allies; corrupt policemen; and cartel members, including the three hit men whose testimony was heard on Friday.
The three told how they were handed the 43 students by the Iguala police force – who had seized them on the orders of the mayor, Jose Luis Abarca, and his wife Maria de los Angeles Piñeda. Mrs Piñeda was holding a rally on the night of September 26, and was said to be concerned that the students would interrupt her moment in the spotlight.
The hit men initially thought that the 43 students were from a rival gang. But, even on hearing the students protest their innocence, they did as they were told and got rid of them – taking them from the police cars into which they had been bundled, and forcing them into a truck. They were so tightly-packed, said El Chereje, that 15 died of suffocation in transit from Iguala to the rubbish dump in neighbouring Cocula, known poetically as Hoyo de Papayo - Papaya Hole.
Those that survived were led down into the dark hollow, and were shot.
"Then we put some rocks on the ground, so that there was a tall ring of stones," he said in his filmed testimony. "Then we put wood in the middle. Then the bodies on top of that – one plank, then a body, then a plank and so on until all the bodies were on it.
"We covered the bodies with diesel and petrol, and set fire to it.
"And then they said to me I should go and find bottles or plastic so that the fire doesn't go out, so I went around the tip finding bottles and wood and threw it on the fire."
El Chereje said that the fire burned for six or seven hours – but they had to wait several hours more until the funeral pyre had cooled.
The gang leaders then sent him and his colleagues to scoop up the ashes, filling black plastic bin bags with the remains, which they then dumped in the San Juan river.
Last week that river was a crime scene, with white-suited forensic teams scouring the area cordoned off behind yellow security tape. Every time they found something – a tooth, a fragment of bone – they left a red flag tied to a small stake in the ground.
Since the September 26 abductions, a total of 19 mass graves have been discovered – none of them have, so far, contained the remains of the students. But it gives a scale of the murderous mandate of the mayor, Abarca, who was arrested last week after over a month on the run.
Why did Abarca, according to the hit men, order the killing of the students?
Mr Murillo has described him as being the mastermind of the abductions, working in collusion with the drugs cartels which controlled the valuable heroin and marijuana trafficking routes through his region. He was paid by the cartels to turn a blind eye to their activities; in return they carried out favours – such as the disposal of enemies.
On Wednesday he was tracked down, after over a month on the run, to a shabby house in a suburb of Mexico City where he reportedly gave himself up without a fight, saying "I'm tired of hiding – I can't take it any more."
His wife, who is seen as the power behind the throne, was reportedly less docile – telling the police: "Don't touch me! Who do you think you are?"
One of their three daughters, Yazareth Abarca Pineda, was arrested alongside them – her social media boastings of trips across Latin America serving as proof of the family's lavish lifestyle. Abarca had rapidly risen from a sombrero salesman to political kingpin – acquiring at least 65 properties in the process, including a ranch, a series of jewellery shops and a shopping centre. His mother-in-law claimed in a video posted on YouTube that this was funded by £92,000-a-month payments from the Guerreros Unidos cartel, which control the area.
Miss Abarca was later released without charge, but her father was transferred to Mexico's most notorious high-security prison, Altiplano, which among its 724 prisoners houses the heads of all the leading cartels – "El Barbie," chief of the Beltran Leyva Organisation; the Arellano Felix brothers, who controlled the Mexico-US border route at Tijuana; Miguel Ángel Treviño, leader of the vicious paramilitary Zetas.
Until Thursday the most famous prisoner was Mexico's previous "most wanted" – Joaquin Guzman, or El Chapo, the world's biggest drugs dealer, who was arrested in February. Now Abarca could stake a claim to that title.
And up until the Iguala scandal, the Mexican president had revelled in taking down the drug lords – portraying it as a triumph of his rule.
Now he is being challenged again.
"The government of Peña Nieto will not be able to explain what happened to the 43 unless it also clears up these links between the political and the criminal," wrote Jorge Carrasco Araizaga in an editorial for Proceso magazine.
He has, in return, promised a "Security Pact," bringing together all the governors of Mexican states to promise to root out criminal collusion.
"To the parents of the young people who have disappeared, and to all Mexicans, you have my word: we will not rest until justice is done," he wrote on Twitter on Friday.
The hit men knew what they were doing when they descended into the abyss. The question is: does the president know how to lead his people out of it?