Automating Society Report 2020


In Spain, the VioGén algorithm attempts to forecast gender violence

by Michele Catanzaro

As part of a program to curb feminicides, Spain built VioGén, an algorithm that assesses the risk faced by victims of gender violence. It remains a work in progress.

In the early morning of 24 February 2018, Itziar P., a psychologist living in the Spanish city of Castellón, went to a police station to report threats from her husband, Ricardo C..

In audio recordings she made with her mobile, the husband could be heard saying: “We will all end up dead and me in jail,” or “I will take away from you what you love most.”

According to Itziar P., Ricardo C. had also broken in pieces the buggy of their smaller child (Martina, two-years-old) and slapped the older one (Nerea, six-years-old) when both children were in his custody.

The police officer asked Itziar P. a set of questions and fed the answers into VioGén, a piece of software that helps the Spanish police estimate the risk of recidivism in gender violence. The officer issued a report in which that risk was deemed as low.

Critical failure

In the following days, both Itziar P. and Ricardo C. were called to declare in court. She asked that he be forbidden to visit their children, but the judge denied the request, based on the low-risk estimation made by the police, among other reasons.

Seven months later, on 25 September 2018, Nerea and Martina were sleeping at Ricardo C.’s place. In the early morning, he killed them “with cruelty” and threw himself out of a window.

Itziar P.’s story was shocking. Why was the case deemed low-risk? VioGén had failed in its role to support police personnel in assessing the risk of new assaults, and, therefore, assigning the right level of protection. Since the software was first deployed, in 2007, several “low-risk” cases have ended in the homicide of women or children.

Better than nothing

The VioGén program is by far the most complex of its sort in the world. It has reasonable performance indexes. Nobody believes that things would be better without it – except the far-right, who make spurious claims that it helps women report innocent men.

But critics point out some flaws. Police officers are seldom educated in gender-based violence, while others blindly rely on the outcome of the software. Moreover, the program may systematically underestimate risk. Some victims’ organizations believe that the possibility of a low-risk score is nonsense. They say that reporting to the police is a high- risk situation in itself because abusers perceive it as a challenge.

As of January 2020, 600,000 cases had gone through Vio- Gén. About 61,000 of them were considered active, meaning they were being followed-up by the police (the system is designed to periodically check on women until they are deemed safe).

Reporting an assault

When a woman goes to report an assault from an intimate partner, she triggers a process that takes at least a couple of hours. First, the police officer goes through an online form with her. The officer ticks each of the items of the VPR form (from the Spanish initials of “Police Risk Assessment”) as “present” or “non-present”. There are 39 items in the latest published version of the form (the VPR4.0). Officers can also rely on police databases, witnesses, and material proofs.

Questions explore the severity of previous assaults (for example, whether weapons were ever used); the features of the aggressor (jealous, bully, sexual abuser, unemployed, drug addict, etc.); the vulnerability of the victim (pregnant, foreign, economically dependent, etc.); and aggravating factors (like assaults by other men).

Answers are thrown automatically into a mathematical formula that computes a score, measuring the risk of whether the aggressor will repeat violent actions. This quantitative approach is different from the one used in DASH, the Brit- ish equivalent of VioGén. The latter is a paper check-list that helps agents to get an idea of the situation.

Keeping the score

In theory, Spanish agents can increase the score manually if they believe there is a higher risk. But a 2014 study found that in 95% of the cases, they stuck to the automatic outcome.

The formula used in VioGén is a “simple algorithm”, according to Juan José López Ossorio, a psychologist who has been in charge of VioGén from its early stages, in a written statement to AlgorithmWatch. The algorithm gives more weight to items that empirical studies have shown to be more related to recidivism, Mr. López Ossorio wrote. He declined to disclose the exact formula.

Once a case’s score is established, the officer decides on a package of protection measures associated with that level of risk. For the lowest scores, officers will discreetly check on the woman from time to time. For the highest, the police will give the victim an alarm button, track the aggressor’s movements, or guard her house. Officers also send the forms and risk scores to the prosecutors and judges that will see the woman’s case.

After the first report, the police meet again with the woman to fill in a second form, in order to assess whether the situation has worsened or improved. This follow-up happens periodically and depends on the risk level. Police only stop following-up if judicial measures are not pursued, and the risk level falls below medium.

VioGén is one of the outcomes of a pioneering law on gender-based violence that Spain approved in 2004, ten years before the Council of Europe adopted a common framework on the subject, the Istanbul Convention. Nowadays, the software is used by the main Spanish police forces (Policía Nacional and Guardia Civil) and by hundreds of local police forces (except in Catalonia and the Basque Country that have independent police bodies).

The best available system

VioGén is the best device available to protect women’s lives, according to Ángeles Carmona, president of the Domestic and Gender-Based Violence Observatory of the Spanish General Council of the Judiciary (CGPJ).

She recalled a case she saw in a court in Seville, of an aggressor who had a high-risk of recidivism, according to VioGén. A control wristband was attached to the man. One day, the police saw that the signal of the wristband was moving fast towards the victim’s home. They broke into the home just in time to prevent him from suffocating her with a pillow.

It’s impossible to know how many lives have been saved thanks to VioGén, according to Antonio Pueyo, a professor of psychology at the University of Barcelona who has advised VioGén from the beginning.

However, a 2017 study by Mr. López Ossorio and his team tried to measure how good the protocol was. They found that VioGén’s Area Under the Curve (AUC), a widely-used measure of performance for predictive models, stood between 0.658 and 0.8. An AUC of 0.5 is as good as the toss of a coin, and an AUC of 1 means the model never fails. Cancer screening tests are considered good when their AUC is between 0.7 and 0.9. In other words, VioGén works.

“Compared with what is around and within the existing limitations, VioGén is among the best things available,” says Juanjo Medina, a professor of quantitative criminology at the University of Manchester, who has compared instruments that assess the risk of intimate partner violence.

Spain is the only place where victims can be followed-up across different regions. Close to 30,000 police officers and other agents across the country had access to VioGén in 2018.

However, the cases that have slipped through the cracks of VioGén have raised concerns. The latest one happened in February 2020, when a 36-year-old woman, and mother of two, had her throat cut by her former partner, who then threw her body in a container in the town of Moraira. The two had been registered in the VioGén system after the police reported him for attacking her, but the case had become inactive after a judge cleared him.

False negatives

In 2014, the newspaper El Mundo published a leaked document from the General Council of the Judiciary that showed that 14 out of 15 women killed that year, having reported their aggressor before, had low or non-specific risk (the classification used for any person reporting a threat to the police).

Some critics say that low-risk should not even be an option. Reporting is a maximum risk moment for a woman, according to Carme Vidal Estruel, spokesperson of Tamaia, an association that helps victims in Barcelona. She says that the situation is akin to divorcing or becoming pregnant, both moments in which the aggressor realizes that he is losing grip on the victim.

Another widespread criticism is that few officers among those who should validate the computer’s outcome receive enough training in gender issues. Some VioGén items are embarrassing, like those related to sexual violence, humiliation, or intimate messages on mobile phones.

Officers should ask circular questions (instead of blunt, direct questions) and avoid transmitting the feeling that the object of investigation is the woman, according to Chelo Álvarez, president of Alanna, an association of former victims in Valencia. Ms. Carmona of the General Council of the Judiciary recalls a woman who reported her husband for robbing her car keys. She was so scared that she could not say anything else. The day after, the man killed her.

Few officers are aware of these nuances. In 2017, there was a total of 654 officers in the whole of Spain attached to the Women-Children Teams (EMUME) of the Guardia Civil. That is much less than one for every police station.

Ignored requirements

This situation is very different from what the 2004 law that created VioGén required. According to the law, cases should be dealt with by an interdisciplinary team, including psychologists, social workers, and forensic doctors.

This team should go into psychological aspects that the Vio- Gén form does not cover. Moreover, the team should carry out a forensic assessment of the aggressor. Critics point out that the current system evaluates how dangerous a person is, without ever talking to him. Several teams were created after the law was passed in 2004, but the process was cut back, following the 2008 financial crisis.

Mr. Pueyo, the psychology professor, acknowledges some of the criticism but believes that VioGén should be judged on its ability to predict new assaults, not homicides, because these events are very rare. The probability that a woman will be killed, after reporting, is about one in ten thousand, according to Mr. López Ossorio.

However, the Istanbul Convention seeks to reduce the risk of death, and not only of women but also of children. Overlooking the risk to children is another criticism VioGén faces.

The convention came into force in Spain in 2014, but Vio- Gén forms were not changed accordingly until Itziar P.’s case in 2018, according to her lawyer.

VioGén 5.0

A new protocol was put in place in March 2019, the fifth big change VioGén has gone through since its first deployment in 2007. Now, the program identifies cases “of special relevance”, in which the danger is high, and includes cases “with minors at risk”.

This is done through the “dual evaluation procedure” of the new VPR form (VPR5.0-H), Mr. López-Ossorio explained. Two calculations are carried out in parallel: one related to recidivism and a new one related to lethal assault.

Depending on the outcome of the latter (called the “H- scale”), the risk score increases automatically. Moreover, the case can then be signaled to the prosecutors and judges as being “of special relevance”.

Mr. López-Ossorio declined to disclose how the H-scale was built, but he wrote that it was based on a four-year study his group carried out to find which factors specifically relate to cases that end up in homicides.

The new protocol seems to have triggered a major shift in the risk scores of VioGén. Passing from VPR4.0 to VPR5.0-H, the number of extreme risk cases rose, and those of high risk almost doubled, according to Mr. López Ossorio.

As the president of Valencia’s former victim’s association, Ms. Álvarez puts it: “Things are improving, but they should go faster because we are being killed.”


Michele Catanzaro

Michele CatanzaroMichele Catanzaro is a freelance journalist based in Barcelona, Spain. He has a PhD in physics, has written for Nature, El Periódico de Catalunya, Süddeutsche Zeitung, and other outlets, and he is the co-author of the book “Networks: A Very Short Introduction” (2012) and the documentary “Fast Track Injustice: The Óscar Sánchez Case” (2014), that received the Golden Nymph Award in 2015. His work has also been recognized by other awards: King of Spain International Journalism Prize, BBVA Innovadata, Valors, European Science Writer of the Year 2016, Prismas, and Colombine. He has received grants from the Journalism Fund, Journalism Grants, and Climate Investigation Grants. He has experience in teaching, exhibitions, TV, and events, and he coordinates the PerCientEx project on excellence in science journalism in Spain and Latin America. He was also a Journalist in Residence at the Heidelberg Institute for Theoretical Studies.