Joaquín “El Chapo” Guzmán, accused of being the world’s biggest drug trafficker, could be found guilty as soon as next week by a jury in New York, and begin his sentence in a jail cell from which – this time – there will be no escape.

Lead prosecutor Andrea Goldbarg said in closing statements on Wednesday that the United States had presented “a mountain of evidence” against Guzmán. In his retort, defence attorney Jeffrey Lichtman pointed out “a 600lb gorilla in the room: reasonable doubt” – the bar below which a guilty verdict falls.

Goldbarg, who has worked on the prosecution of other major narco-traffickers – including one of her witnesses here, Colombian Jorge Cifuentes Villa – spoke before an array of AK-47s and bricks of cocaine on the table in front of her, reminding jurors of the narratives of money, murder, torture and bribery that have unfolded over the past three months.

Lichtman – who secured a partial acquittal of mafioso John Gotti in this court – echoed the theme with which he opened: that Guzmán was framed by his cofounder of the Sinaloa cartel, Ismael “El Mayo” Zambada García, who, he alleged, remains its real leader. He said the trial’s most politically charged detail – a $100m bribe paid in 2012 to then incoming president Enrique Peña Nieto – came not from Guzmán, as testified, but Zambada.

“Tell me, who do you think paid that bribe?” Lichtman asked the jury, “the man hunted like an animal for years after the bribe was supposedly paid, or the man who was free for decades?”

Peña Nieto has denied taking bribes, as has his predecessor Felipe Calderón, who was named in opening statements as having also been compromised, though further detail was ruled inadmissible by Judge Brian Cogan.

Lichtman again assailed the prosecution’s “snitch” witnesses, who testified after striking deals to reduced sentences. “These witnesses lie, steal, cheat, deal drugs and kill people”, he said, and “they lied while they were cooperating … We have to trust the word of these lunatics?”

Prosecutor Amanda Liskamm, in rebuttal, called Lichtman’s argument a “distraction”. “The defence is pointing fingers everywhere,” she said, “except where the evidence points.”

But the curiosity of this trial is that much in these apparently contesting accounts can both be true.

The jury is likely to agree with Goldbarg that Guzmán was indeed “running” the cartel – inasmuch as any individual can manage a corporation as vast as this one: the Sinaloa cartel was also known as “La Federación”, an alliance of factions, both its strength and ultimate weakness.

It was hydra-headed: Lichtman may also be correct in asserting that El Mayo ran the cartel – though also not alone. One compelling witness was Jesús Zambada García, El Mayo’s brother and the cartel accountant, who laid out with the cool aplomb of an astute businessman particulars of his delivery overheads and profit margin targets, stressing that he preferred to secure five investors for each consignment: his brother, Guzmán and three other cartel leaders.

Lichtman may also be right in at least a variation on the theme of his theory that El Mayo made Guzmán the “fall guy”. Word abounds in Mexico that Zambada “delivered” Guzmán, or at least sabotaged his official protection, after the two fell out: El Mayo was especially angry about the lack of plans for a credible succession, and a film Guzmán proposed making about himself, discussed with the actor Sean Penn.

Both sides probably agree on the trial’s driving theme, their difference being its legal relevance: in cross-examination of the 11 “snitch” witnesses, the defence sought to put the corruption of Mexico’s polity, military and police in the dock, in lieu of its client.

The strategy is unlikely to bear successfully on the verdict, but the exposure of corruption throughout the Mexican state apparatus will be the trial’s principal legacy – whether as revelation to those surprised, or affirmation to those who knew all along.

Apart from the allegations against presidents, the court heard that the man in charge of Mexico’s anti-drug enforcement, Genaro García Luna, was on Guzmán’s payroll. The former army general Gilberto Toledano was allegedly paid regular installments of $100,000 to clear a flow of drugs through terrain under his command. Federal and highway police escorted Jesús Zambada’s imports from Colombia – and so on.

Evidence dovetailed into what is already on record to build an illuminating picture of how Mexican corruption works in tandem with stronger cartels, over generations. The story of one corrupt officer made the point well: two witnesses testified that the first official Guzmán “bought” in the late 1980s was Guillermo González Calderoni, the chief of Mexico City’s federal police.

A Guzmán lieutenant, Miguel Ángel Martínez, testified that chief Calderoni furnished El Chapo with daily information, including a tip that the US had built a radar installation in Yucatán to track shipments from Colombia, and intelligence on tunnels beneath the border.

Calderoni became a hero in Mexico for helping US authorities crack the case of Enrique Camarena Salazar, a DEA agent kidnapped, tortured and killed by Guzmán’s mentor, “Godfather” Félix Gallardo. Yet the court heard that within two years of that murder, Calderoni was already accepting cartel bribes.

But we know Calderoni was compromised long before: in a diary written by Gallardo himself and published in Gatopardo magazine in 2011, the godfather describes Calderoni as “a friend” throughout the 1980s until he betrayed him.

Calderoni was shot in the head while sitting in his car on a street in McAllen, Texas, in 2003. The authorities have never identified his killer.

The trial gave a tantalising glimpse into this wider world – but the prosecution was eager to keep as focused and narrow as possible, with agreement from the bench.

Under the terms of the “kingpin strategy” against narco-trafficking, Guzmán’s conviction would mark a mighty blow to drug-dealing. But it is testimonies like that on Calderoni which will outlive the proceedings in Brooklyn.

Guzmán disappointed many when he told Judge Cogan he would not testify. But El Chapo had already said all he needed to say, when he told Sean Penn that – whatever happens to him – “this will never end”.