It’s a favourite current joke in Mexico: “No más túneles!” – no more tunnels. There’s little chance of drug lord Joaquín “El Chapo” Guzmán Loera repeating his famous escapes from Mexican prisons in the US jail where he was sent after being given a life sentence last week by a court in Brooklyn.

So now that El Chapo is removed from the scene, what next? The pillar of the US “Kingpin” strategy against narco-traffic is that the trade is weakened when its leaders are caught and jailed.

Guzmán’s Sinaloa cartel has indeed imploded, the strength of its outreach as a “federation” – as it called itself – becomes a weakness, as factions fight for the succession and its co-founder, Ismael “El Mayo” Zambada, struggles to keep control.

But in narco-land violence intensifies when sands shift, and the trafficking “plazas” are open to challenge. Last year, that after El Chapo’s conviction in New York was the most murderous yet in Mexico since President Felipe Calderón launched the latest phase of the US-backed “war on drugs” in December 2006: 33,341 killings, 33% up on 2017, the year Guzmán was extradited.

A powerful new syndicate rises: Cartel Jalisco Nueva Generación – its leader, Nemesio “El Mencho” Oseguera Cervantes, still at large – which cut its teeth trading synthetic drugs and heroin in Asia and Europe.

Much of the bloodletting is for so-called narcomenudeo turf, the domestic market. In Mexico’s homicide capital city, Tijuana (taken around 2010 by the Sinaloa cartel, but now lost), the veteran mafia expert Victor Clark Alfaro observes: “The cartel leaders are nowadays business people you’d meet at the country club. For the first time in three decades, I cannot name their leaders to you. They’re not necessarily the ones killing each other; it’s that they’ve lost control of the low-level street dealers.”

“Why should they care?”, asks Alfaro. “They know that every time 10 people are killed on the street, 10 more will take their place. What matters to them is the money.”

Drugs keep flowing after El Chapo’s sentencing – more coca than ever from Colombia, plus the CJNG’s switch back towards heroin and strength in the market for its synthetic form, fentanyl. And so does the money, both in cash to Mexico from ever-adapting distribution and retail networks in the US, and back north across the border through the banking system. The task after El Chapo’s trial is the search for his money, in the former direction – but [authorities seem] happy to let the latter well alone.

More interesting than the sentencing itself was a 12-page document on forfeiture submitted by prosecutors just ahead of it. The calculations are estimably meticulous: El Chapo’s products in the US, they say, were worth $12,666,181,704. The figure is extrapolated from evidence at the trial of “snitch” witnesses who knew the value of what they were shipping.: cartel accountant Jesús Zambada, El Mayo’sbrother, who detailed investments and profit margins for different US cities, and suppliers Juan Carlos Ramírez and Jorge Cifuentes Villa.

Prosecutors will not disclose how and where they will seek this fortune, but the former head of anti-money laundering for the Manhattan district attorney’s office, Duncan Levin, gave the Observer an insight into how they might proceed.

“Forfeiture is part of a sentence,” says Levin. “If there are assets in the US, they can go right after those assets.” He adds that a US law from 1957 provides for any asset partly funded by criminal money to be seized in its entirety. “The way they did business was very pervasive,” he says. So that any business in which the Sinaloa cartel is found to have invested is fair game.

But, says Levin, “the vast bulk of assets are likely in Mexico” and the search for them “would be greatly helped by working with the Mexican government”, despite current political tensions.

While the court heard mostly about movements of cash by Guzmán’s operatives, Mr Levin posits numerous other channels prosecutors might examine on what he calls “the black market Peso exchange… for example: pre-paid debit cards, so all you have to smuggle is a piece of plastic in your wallet, loaded with a million dollars” or “goods: you buy several thousand laptop computers and export them. The money comes from their sale in Mexico”.

The prosecutors’ forfeiture document calls the figure “conservative”; we will never know how much the Sinaloa cartel or its rivals is worth.

But absent from any Department of Justice pursuit of El Chapo’s fortune, and from any evidence at trial, are the billions invoked and cited by its own cases against the Wachovia and HSBC banks since 2010. Both cases ended in deferred prosecutions, fines minute in relation to annual turnover and scolding of mid-ranking executives, but no trial.

The narco-fortunes laundered through both banks are considered, as Levin says, “case closed”.