Jeffrey Epstein is dead but the investigation that snared on sex trafficking charges has continued as authorities seek to make good on their promise not to let the convicted sex offender’s apparent suicide mark an end to their quest for justice.

Given the nature of the wealthy financier’s elite international social scene, it’s possible potential co-conspirators or other participants in the alleged trafficking would have the means to flee into hiding, in the US or abroad.

Investigators on any potential manhunt would have at their disposal a range of tools, from facial recognition software and sophisticated techniques to track their finances.

But the international character of some of Epstein’s accused enablers begs the question: how would authorities find potential co-conspirators in hiding? If they fled the US or live abroad, how would authorities catch them?

So far no one else has been charged in relation to Epstein’s alleged sexual abuse of minors as young as 14 at his Manhattan and Palm Beach, Florida, homes. But the names of other possible co-conspirators have repeatedly surfaced in court documents and media reports. The highest profile is Ghislaine Maxwell, the British socialite long accused of procuring girls for Epstein – an allegation she has emphatically denied.

Jeffrey Epstein and Ghislaine Maxwell at Ciprani Wall Street in New York City on 15 March. Photograph: Patrick McMullan/Patrick McMullan via Getty Images

Former federal law enforcement agents said that catching any wanted persons relies on traditional police work, the use of technology and close relationships with law enforcement agencies in other countries – not thriller movie-style tactics such as throwing a fugitive in the trunk of a car.

The US Marshals Service is the main federal agency tasked with tracking and extraditing persons facing charges in the US who have fled abroad.

US law enforcement does not have jurisdiction in foreign countries, so the first step – finding these wanted persons – takes place stateside and in some field offices, according to the Marshals Service.

To track a wanted person, “one of the things you always do is follow the money”, said Clinton R Van Zandt, a former FBI criminal profiler and current corporate security expert. “An individual has to have money to function overseas. That money has to be in a bank account. It has to be wired from point A to point B.”

The financial instruments and personal documents people need to function – such as credit cards and passports – can tip off authorities. Facial recognition software allows authorities to take “the image of the face of the fugitive and run that against tens of thousands of individuals”, Van Zandt said.

It’s fairly hard today to just drop out totally unless you’re willing to go to some third-world country Clinton R Van Zandt

“You and I can’t walk anywhere in this world without leaving some type of digital footprint or fingerprint – it’s just almost impossible to do,” Van Zandt said. “It’s fairly hard today to just drop out totally unless you’re willing to go to some third-world country and live far below your economic means, change your appearance and never get stopped and never get arrested.”

Mary Ellen O’Toole, a former FBI profiler who played an integral role in tracking down the Unabomber, said wanted persons are in a no-win situation when it comes to interacting with others.

“Law enforcement will be looking at people who are likely to be able to help this person, who might stick their neck out to help this person,” said O’Toole, who heads the forensic science department at George Mason University in Virginia.

Epstein’s elite former associates might find their wealth and status now becomes a disadvantage. Other rich and famous people might well see this person as a liability – potentially making them more likely to tip off authorities.

“If you run in a circle of very high-profile people, that means these people are well-known,” she said. “That means these people have a lot to lose to associate with you.”

Joseph King, formerly a supervisory special agent with US customs in New York and former chief, national security section for the Department of Homeland Security in New York, said authorities can also use a “trap and chase” to locate a wanted person based on communications with past associates.

“Let’s say I’m a fugitive, but they know that I speak to you,” he explained, “so they track all of your phone calls, and try and trace you back to their location.”

If US authorities did locate someone abroad, they would inform foreign authorities. If US law enforcement had a good relationship with authorities in that country – and if there weren’t legal issues surrounding extradition – authorities abroad would generally help arrest those wanted persons.

In some cases, US marshals are present for the arrest, the agency said.

While Interpol does not investigate wanted persons whereabouts, it works “to support police with any international aspects of their investigations”, the agency said in an emailed statement.

While US law enforcement doesn’t have jurisdiction abroad, authorities sometimes use informants and subterfuge to track and catch wanted persons on foreign soil.

“I place a high value on informants, not just on luring people but on information on their whereabouts,” said King, who is an associate professor at John Jay College of Criminal Justice in New York City.

If a person can’t be extradited for some reason, an informant could be used to bring that person into US jurisdiction.

“We couldn’t get this Iranian out of England, so my informant said to him: ‘Let’s set up a business deal.’ He said they were going to incorporate this company in Bermuda,” King recalled of one case. “Instead of going to Bermuda, the flight he was on was London-New York-Bermuda.”

When the flight stopped in New York, “we just took him off the plane and arrested him”, King said.

Private bounty hunters, however, are not controlled by US federal laws on extradition.

While private bounty hunting is against the law in some foreign countries, US judges might not have a problem with a fugitive being apprehended in that manner.

“If a [bounty hunter] dropped them at the foot of a courthouse, it would depend what a federal judge would ask.” King said. “Were they acting as an agent of the government? Or were they completely independent individuals?”

At times, bringing a wanted person back to the US could be a matter of negotiation.

Jennifer Louis-Jeune, a criminal defense lawyer in New York City, said a wanted person out of the country may have a lawyer appointed to guide the process. A person might also broker an individualized deal to return to the US.

“Those may involve deals such as the United States agreeing that they won’t pursue the death penalty if the person’s extradited,” Louis-Jeune said.

But no matter the difficulties that may arise, the investigation will probably not stop. It has the public support of America’s top law enforcement official.

“Let me assure you that case will continue on against anyone who was complicit with Epstein,” said the US attorney general, William Barr. “Any co-conspirators should not rest easy. Victims deserve justice and will get it.”