He is a regular guest in newspaper headlines, his authority is invoked by many and many fear him - the polygraph, or lie detector, has been one of the most important apparatuses in Serbian politics for decades.
The trial of Darko Šarić, the murder of Oliver Ivanović, irregularities in Serbian football, media fights, the Krusik and Jovanjic affairs, the arrest of Veljko Belivuk, as well as the alleged wiretapping of Serbian President Aleksandar Vučić.
Those cases have something in common - the polygraph stood out as the ultimate piece of evidence in each of them.
"Bring the polygraphist you want, from which country you want, and I will answer every question for Jovanjica," replied Serbian President Aleksandar Vučić to accusations of ties to this organic food farm where a huge marijuana plantation was found in 2019.
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In recent years, the use of the polygraph has become more and more widespread in Serbia and the world - the police use it in investigations, companies to check candidates before employment, and people for private purposes, most often because of suspicion of the infidelity of a loved one.
"The polygraph is used to check someone's claims and whether someone is telling the truth," polygraphist Nikola Novak told the BBC in Serbian.
However, a polygraph can only be taken voluntarily in Serbia and it has no weight in court.
"The court cannot base a verdict on the basis of a polygraph, it has no probative value," lawyer Predrag Savić explained to the BBC in Serbian.
However, he says, the polygraph can be very useful in police investigations.
Đorđe Pavićević, a professor at the Faculty of Political Sciences, believes that the polygraph is often "presented as evidence that is more powerful than both police investigations and court verdicts".
"It has become part of the standard manipulation when the government wants to either accuse someone or amnesty themselves from accusations," Pavićević told the BBC in Serbian.
How does the polygraph work?
The one who is sincere and honest will endure boiling water on his skin better than the one who lies, it is stated in text Lie detectors and the polygraph: A historical overview.
This is what, among other things, "polygraph testing" looked like in the Dark Ages.
In the meantime, technology has progressed, and at the end of the 19th century, a device was created that, by measuring blood pressure, should determine whether a person is telling the truth.
The idea was that if the person is not telling the truth or hiding something, the pressure will be high.
The first versions of the polygraph, which measured several physiological parameters at the same time - both breathing and blood pressure - appeared a few decades later.
Modern polygraphs, which are used today, function on a similar principle as their ancestors, only they measure even more parameters at the same time.
"The scientific name of the test is psychophysiological detection of deception," says Novak from the Polygraph Center, a company that deals with polygraph testing.
Novak says that people's natural state is to tell the truth, which is why it takes more mental energy to tell a lie.
In order to agree, he states, we have to create something that does not exist, which will always produce a physiological reaction in the body.
"Especially if we see everything that happens as a threat, because there must be some consequence of failing the polygraph test - people are afraid of being caught in a lie, of losing their job, reputation," says Novak.
Testing in practice looks like questions are defined "in a controlled environment" and the examinee answers them exclusively with da or ne.
During that time, the polygraph measures a series of physiological parameters that, according to Novak, will show if the person is lying.
There are five basic channels, he explains.
"The first measures breathing patterns, the second the heart rate, the third the frequency of sweating, the fourth the conduction of blood between the organs, and the fifth is for catching countermeasures - if someone is doing something to sabotage the test," he says.
According to him, the respondents tried to deceive the polygraph in several ways: mentally (with psychological exercises), physically (when a person inflicts pain on himself, for example) and pharmacologically (with medicines or drugs).
"We see it all," claims Novak.
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What a polygraph examination looks like
Petra Živić, BBC journalist
I took a polygraph test in 2015.
No, it was not about anything official, no one checked the credibility of my claims, but I, as one of the youngest journalists in the then editorial office, told me to write the text what the famous polygraph looks like firsthand.
For the needs of the text, we hired a private agency for polygraph tests from Belgrade, whose founder visited the newsroom and brought a polygraph in a suitcase.
Said I had to sit quietly, with my back straight, and then he started "connecting" to the polygraph.
He explained to meand that they will attach a device that measures heart activity, then a belt that measures chest and stomach breathing.
I remember that, first of all, he told me that the polygraph test was "the art of conversation," which intrigued me.
But not for long.
He explained that I could only answer yes or no and started with general questions about me - name, surname, year of birth, where I work.
I answered yes to everything he asked.
Then he asked questions that I couldn't answer with yes or no, already required additional explanations which, as he explained to me, they don't practice when the polygraph examination is in the middle.
When he started asking me aboutdquestions about my private life, I already started laughing because I didn't see the point in it all.
Laughter ruined the whole test - he explained to me that my laughter made it impossible to adequately measure the parameters and that he would have to repeat the test.
As he had nothing concrete to investigatee I refused second round.
In the company for polygraph tests, they believe in the power of lie detectors, but not everyone is convinced that this is so.
"It is absolutely possible to deceive the machine," says lawyer Savić.
Savić refers to Živojin Aleksić, a professor at the Faculty of Law and the originator of criminology as a science in Serbia.
As he says, Aleksić believes that it is possible to influence the work of the polygraph primarily psychologically, and that the result can be influenced by the incompetence of the examiner and poorly composed questions.
Critics of the polygraph state that the relationship between physiological parameters and lying is questionable, as well as that they can be increased even when someone is not lying.
Professor Aldert Vridge, from the University of Portsmouth, who has dealt extensively with this subject, he told the BBC earlier that "the polygraph does not measure deception itself, which is an essential problem".
"The idea is that liars will have elevated parameters when answering substantive questions, and truth tellers will not, but there is no scientific theory that supports this," he says.
He thinks the same psychologist Sophie van der Zee, pointing out that "there is no human equivalent of a Pinocchio nose," and that the polygraph measures "the indirect effects of lying, which can cause stress."
Novak does not agree with that.
"The physiological reactions we are testing are part of the hypothalamus, the part of the brain that at any given moment controls more than 140 processes in the body, such as the functioning of organs."
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He claims that this "instinct for reaction has been innate in humans since prehistoric times."
"An organism faced with a threat can deal with it in three ways - to fight, to flee or to freeze - but there will always be some reaction.
"When the senses register a threat, then the system automatically raises the heart rate and prepares the body for a fight, another part releases sweat to cool it, adrenaline rises... There are always consequences".
That's why, he says, the difference between an average and top polygraph examiner is how to see the difference between stress and a reaction to a lie.
"The non-verbal signs that the body emits under stress and when it is calm are identical, so they are not taken as an element in the assessment," he states.
He is aware, he adds, that it is not pleasant to take a polygraph and that everyone is excited when they are tested, but he claims that it has nothing to do with the final results.
"At least three tests are done in a row, one can show a reaction that cannot be explained, but the coincidence cannot be repeated three times," says Novak.
The website of the Polygraph Center points out that the polygraph "like all other forensic methods is not 100 percent accurate and precise".
"With analog equipment, the accuracy was around 65 percent, with computerized polygraphs it was around 95 percent, and with the latest instruments it was up to 97 percent," they state.
What does the law say?
Prema Law on Police polygraph examination falls under "police measures and actions".
"Voluntary consent of the subject" is necessary, and the law determines who can be subjected to a polygraph.
For example, those under the influence of alcohol, drugs or tranquilizers, with heart or respiratory problems, pregnant women and women in labor cannot take a polygraph.
They cannot be interrogated either under the age of 14, nor those who "show visible signs of mental illness".
Savić says that the polygraph in the investigation can be of great importance to "exclude or prove the facts and circumstances related to the commission of the criminal act".
"Nevertheless, other evidence is also needed - the court cannot base a verdict on the basis of a polygraph," he says.
"It can only be done on the basis of reliable evidence, and the polygraph is not reliable evidence".
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One of the obstacles to the introduction of polygraphs into courts is the aspect of human rights, he states - for example, the right of the accused to defend himself by remaining silent.
And for the position of the polygraph in the Serbian legislation, he says, Professor Aleksić is primarily responsible.
"He was a pioneer of polygraph analysis and one of the reasons why the polygraph and other disciplines that today belong to forensics were adequately studied," says Savić.
As he says, Aleksić warned about the relative probative power of the polygraph.
Savić also states that the polygraph first arrived in the former Yugoslavia in 1959 in Ljubljana, and that polygraph centers were soon built in Belgrade and Zagreb.
"Already during the seventies, it was used in police investigations and criminalistics as an operational-tactical tool," he says.
Politics - who agreed and refused the polygraph?
The polygraph has been talked about in Serbia for a long time, but especially in the last few weeks.
For example, because of the Jovanjica case.
"I'm going to invite all of you, bring the polygraphist you want, from which country you want, and I'll answer every question about Jovanjica." Serbian President Aleksadnar Vučić told Pink.
For years, the company "Jovanjica" was known for the production of organic food, but at the end of 2019, the police discovered that marijuana was also produced there.
Because of this, Predrag Koluvija, the owner of the company, was arrested, and the Prosecutor's Office for Organized Crime filed two indictments.
One against Koluvia, and the other against eight persons, among whom are police officers, members of the Security Information Agency and the Military Intelligence Service.
Because of this, certain opposition parties accuse the top of the state of close cooperation with Koluvia, which President Vučić denies and announces his readiness for a polygraph examination.
Professor Pavićević believes that the polygraph is "one of the usual manipulations of the authorities, when they want to accuse someone or grant amnesty".
"That manipulation sounds good to those who are either not very knowledgeable, or don't follow political events closely," he says.
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The polygraph won the front pages of the tabloids even after the recent arrest of Veljko Belivuk, also known as the leader of the Partizan fans.
In the days after the arrest, the Service for Combating Organized Crime questioned several people about their relationship with Belivukova.
They are among them Vladimir Vuletic, former vice president of Partizan, who resigned from that position after Belivuk's arrest, as well as Diana Hrkalović, former State Secretary in the Ministry of Internal Affairs of Serbia.
In the end, Slaviša Kokeza, president of the Football Association of Serbia, allegedly close to the ruling Serbian Progressive Party, was also heard.
According to the tabloid, both Vuletić and Hrkalović agreed to take a polygraph test, but could not for health reasons, while Kokez refused.
Pavićević says that numerous media are actually "actors playing with one side".
"They develop, market and further develop what the government wants," says Pavićević, adding that the problem is not in the polygraph at all.
"What is even more worrying is that we see that the media, the police and the government are playing on the same side in this sense," the FPN professor believes.
One of the most famous polygraphic cases in Serbia, it happened in 2014, after the arrest of Darko Šarić, who was later convicted of drug trafficking.
Šarić then named Rodoljub Milović, the head of the Criminal Police Directorate, as one of his collaborators, which Milović denied.
Both Milović and Šarić then took a polygraph - and both passed the test, although they claimed two opposite things.
Four years later, after the murder of the Kosovo politician Oliver Ivanović, Milan Radoičić also took a polygraph, for whom the Kosovo authorities issued a warrant for suspicion of connection with the assassination.
"He passed the polygraph and it was established that he is not the perpetrator, nor the organizer of that crime," he said 2018. Marko Đurić, then director of the Office for Kosovo and Metohija, now ambassador to America.
The warrant for Radoičić was canceled at the beginning of March this year.
Milan Radoičić is the vice-president of the Serbian List and a controversial businessman, who is considered one of the most powerful people in Kosovo and Metohija.
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A President Vučić was already on the polygraph in 2015, when he denied the Kurir newspaper's accusations that he participated in the extortion and blackmail of the newspaper's former director.
His willingness to take the polygraph test that year was also emphasized Sinish Mali, then the mayor of Belgrade, and now the minister of finance, regarding accusations that he bought 24 apartments in Bulgaria.
He said the same former Minister of Police and now Minister of Defense Nebojša Stefanović regarding the Krusik affair,
It is about a story from 2019 about how the GIM company, which is associated with Stefanović's father Branko, bought weapons at preferential prices from the state-owned enterprise "Krušik".
That information was published by Krusik employee Aleksandar Obradović, who was then arrested for revealing secret information.
Application of the polygraph
Nikola Novak, polygrapher
A polygraph may be used in post-incident situations, when, for example, theft at work has already happened, in order to determine who did it.
There are also frauds and adulteries, although that is the least we like to do.
It is used more and more for preventive purposes, for example pre-employment checks.
Companies that deal with confidential information when entering a company want to know if you work for a competitor, if you have stolen from former employers...
In such companies, there are often periodic checks, say every six months, whether you have sold any information to the competition and the like.
Kit is also worn when entering the police, security services, agencies dealing with the fight against corruption...
It can be used and for therapeutic purposes, for example in the treatment of pathological gamblers or drug addicts.
Practice in the world
The use of the polygraph in Europe varies from country to country, but it generally cannot be used as evidence in court.
In England and Wales, for example, it is mostly used in the control of prisoners who are on parole, most often sex offenders.
If they fail the polygraph test, it does not mean they are lying, nor do they immediately go back to prison, but it could lead to further investigation.
In this way, 166 sex offenders returned to prison, the British Ministry of Justice announced in 2018.
Similar measures are being considered when it comes to people convicted of domestic violence.
And by far the largest user of polygraphs in the world is America.
Portal Wired announced in 2018 that 2,5 million polygraph tests are taken annually in America, which is a two billion dollar industry.
"America has gone the furthest with that application, they have decades of practice," says Savić.
Several US states accept polygraph examinations as evidence in court, although this remains controversial.
It is mostly used, as in England and Wales, in the supervision of people who have already been convicted.
Novak says that the problem here can arise due to "habituation".
"Sex offenders who constantly have to take polygraph tests get so used to it that they are completely relaxed after a large number of tests," he says.
Somewhat weaker application of the polygraph exists in Israel, Japan and India.
In 2008, an Indian court accepted a polygraph test as evidence in a case against a woman accused of killing her fiance.
Then in 2010, the Indian Supreme Court declared the use of polygraph tests illegal and unconstitutional unless there is consent.
"I assure you that more states will accept polygraph testing and that it will be evidence in court - pay attention to what I told you," says Novak.
Why has this not been done in Serbia so far?
"Because we are lagging behind the world in everything, including that, but that will come to us as well. It's just a matter of time," he claims.
Spies and agents
Cases of various spies who were able to cheat the polygraph are also known in the world.
For example, he did that double agent Aldridge Ames, who, as if at the same time, worked for both the CIA and the KGB - to whom he provided secret information.
"There's no doubt it's possible to cheat a polygraph, but you need training to do it," he told the BBC earlier psychologist Don Grubin, from the Institute of Neuroscience at the University of Newcastle, who has long trained polygraph examiners.
"On some sites, there are instructions on how to do it, but if you go to the polygraph hoping to fool him, it won't happen."
Grubin points out that, in addition to training, there are several methods that can be used to conceal a trace, but that most polygraphists will be able to recognize what it is about.
Maybe that's exactly what happened To Harold James Nicholson, a CIA spy who was not so successful in leaking information to other services.
He failed a polygraph test and was later arrested.
However, the testing did not yield results in the case serial killer Gary Ridgeway, who passed the polygraph in 1984.
He only confessed to the murders 20 years later, in the face of DNA evidence.
And it also happened that innocent people failed the polygraph - Bill Wiegerl he failed two polygraph tests in 1986 on the alleged murder of his wife, but was never convicted.
That case followed him all his life, until twenty years later, through DNA, it was determined that the serial killer known as BTK was responsible for his wife's death.
There were also cases when polygraph testing led to the solution of major cases, such as in 2002, when a seven-year-old girl disappeared in San Diego, USA. Daniel van Dam.
The police suspected David Westerfield, who failed a polygraph test, of the crime.
The case later ended up in court and he was convicted of kidnapping and murder.
What next?
The polygraph will continue to be an important tool in police investigations.
"He also helped solve many crimes, but his reliability was never absolute," says Savić.
However, Novak says that it is inevitable that the polygraph will enter the courts.
"It's been in use for 100 years, during which many things have come up with the idea of replacing it," he says.
This means that, as he says, the polygraph is the only one that has stood the test of time.
In the meantime, polygraph tests continue to fill portals and newspapers in Serbia.
Professor Pavićević says that it is possible to change the status and use of the polygraph only if the statement on the polygraph is placed in the right place.
"It's not a matter of media hype and police accusations, but simply something that can help and guide the police investigation.
"Another way is to gain trust in the police, if we can say that they are doing their job, and not that the government, the police and the media are performing political tasks together," concludes Pavićević.
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