Arquivo da tag: Crime

The Reasons Behind Crime (Science Daily)

Oct. 10, 2013 — More punishment does not necessarily lead to less crime, say researchers at ETH Zurich who have been studying the origins of crime with a computer model. In order to fight crime, more attention should be paid to the social and economic backgrounds that encourage crime.

Whether a person turns criminal and commits a robbery depends greatly on the socio-economic circumstances in which he lives. (Credit: © koszivu / Fotolia)

People have been stealing, betraying others and committing murder for ages. In fact, humans have never succeeded in eradicating crime, although — according to the rational choice theory in economics — this should be possible in principle. The theory states that humans turn criminal if it is worthwhile. Stealing or evading taxes, for instance, pays off if the prospects of unlawful gains outweigh the expected punishment. Therefore, if a state sets the penalties high enough and ensures that lawbreakers are brought to justice, it should be possible to eliminate crime completely.

This theory is largely oversimplified, says Dirk Helbing, a professor of sociology. The USA, for example, often have far more drastic penalties than European countries. But despite the death penalty in some American states, the homicide rate in the USA is five times higher than in Western Europe. Furthermore, ten times more people sit in American prisons than in many European countries. More repression, however, can sometimes even lead to more crime, says Helbing. Ever since the USA declared the “war on terror” around the globe, the number of terrorist attacks worldwide has increased, not fallen. “The classic approach, where criminals merely need to be pursued and punished more strictly to curb crime, often does not work.” Nonetheless, this approach dominates the public discussion.

More realistic model

In order to better understand the origins of crime, Helbing and his colleagues have developed a new so-called agent-based model that takes the network of social interactions into account and is more realistic than previous models. Not only does it include criminals and law enforcers, like many previous models, but also honest citizens as a third group. Parameters such as the penalties size and prosecution costs can be varied in the model. Moreover, it also considers spatial dependencies. The representatives of the three groups do not interact with one another randomly, but only if they encounter each other in space and time. In particular, individual agents imitate the behaviour of agents from other groups, if this is promising.

Cycles of crime

Using the model, the scientists were able to demonstrate that tougher punishments do not necessarily lead to less crime and, if so, then at least not to the extent the punishment effort is increased. The researchers were also able to simulate how crime can suddenly break out and calm down again. Like the pig cycle we know from the economic sciences or the predator-prey cycles from ecology, crime is cyclical as well. This explains observations made, for instance, in the USA: according to the FBI’s Uniform Crime Reporting Program, cyclical changes in the frequency of criminal offences can be found in several American states. “If a state increases the investments in its punitive system to an extent that is no longer cost-effective, politicians will cut the law enforcement budget,” says Helbing. “As a result, there is more room for crime to spread again.”

“Many crimes have a socio-economic background”

But would there be a different way of combatting crime, if not with repression? The focus should be on the socio-economic context, says Helbing. As we know from the milieu theory in sociology, the environment plays a pivotal role in the behaviour of individuals. The majority of criminal acts have a social background, claims Helbing. For example, if an individual feels that all the friends and neighbours are cheating the state, it will inevitably wonder whether it should be the last honest person to fill in the tax declaration correctly.

“If we want to reduce the crime rate, we have to keep an eye on the socio-economic circumstances under which people live,” says Helbing. We must not confuse this with soft justice. However, a state’s response to crime has to be differentiated: besides the police and court, economic and social institutions are relevant as well — and, in fact, every individual when it comes to the integration of others. “Improving social conditions and integrating people socially can probably combat crime much more effectively than building new prisons.”

Journal Reference:

  1. Matjaž Perc, Karsten Donnay, Dirk Helbing. Understanding Recurrent Crime as System-Immanent Collective BehaviorPLoS ONE, 2013; 8 (10): e76063 DOI:10.1371/journal.pone.0076063

Brain Scans Predict Which Criminals Are Most Likely to Reoffend (Wired)


03.26.13 – 3:40 PM

Photo: Erika Kyte/Getty Images

Brain scans of convicted felons can predict which ones are most likely to get arrested after they get out of prison, scientists have found in a study of 96 male offenders.

“It’s the first time brain scans have been used to predict recidivism,” said neuroscientist Kent Kiehl of the Mind Research Network in Albuquerque, New Mexico, who led the new study. Even so, Kiehl and others caution that the method is nowhere near ready to be used in real-life decisions about sentencing or parole.

Generally speaking, brain scans or other neuromarkers could be useful in the criminal justice system if the benefits in terms of better accuracy outweigh the likely higher costs of the technology compared to conventional pencil-and-paper risk assessments, says Stephen Morse, a legal scholar specializing in criminal law and neuroscience at the University of Pennsylvania. The key questions to ask, Morse says, are: “How much predictive accuracy does the marker add beyond usually less expensive behavioral measures? How subject is it to counter-measures if a subject wishes to ‘defeat’ a scan?”

Those are still open questions with regard to the new method, which Kiehl and colleagues, including postdoctoral fellow Eyal Aharoni, describe in a paper to be published this week in the Proceedings of the National Academy of Sciences.

The test targets impulsivity. In a mobile fMRI scanner the researchers trucked in to two state prisons, they scanned inmates’ brains as they did a simple impulse control task. Inmates were instructed to press a button as quickly as possible whenever they saw the letter X pop up on a screen inside the scanner, but not to press it if they saw the letter K. The task is rigged so that X pops up 84 percent of the time, which predisposes people to hit the button and makes it harder to suppress the impulse to press the button on the rare trials when a K pops up.

Based on previous studies, the researchers focused on the anterior cingulate cortex, one of several brain regions thought to be important for impulse control. Inmates with relatively low activity in the anterior cingulate made more errors on the task, suggesting a correlation with poor impulse control.

They were also more likely to get arrested after they were released. Inmates with relatively low anterior cingulate activity were roughly twice as likely as inmates with high anterior cingulate activity to be rearrested for a felony offense within 4 years of their release, even after controlling for other behavioral and psychological risk factors.

“This is an exciting new finding,” said Essi Viding, a professor of developmental psychopathology at University College London. “Interestingly this brain activity measure appears to be a more robust predictor, in particular of non-violent offending, than psychopathy or drug use scores, which we know to be associated with a risk of reoffending.” However, Viding notes that Kiehl’s team hasn’t yet tried to compare their fMRI test head to head against pencil-and-paper tests specifically designed to assess the risk of recidivism. ”It would be interesting to see how the anterior cingulate cortex activity measure compares against these measures,” she said.

“It’s a great study because it brings neuroimaging into the realm of prediction,” said clinical psychologistDustin Pardini of the University of Pittsburgh. The study’s design is an improvement over previous neuroimaging studies that compared groups of offenders with groups of non-offenders, he says. All the same, he’s skeptical that brain scans could be used to predict the behavior of a given individual. ”In general we’re horrible at predicting human behavior, and I don’t see this as being any different, at least not in the near future.”

Even if the findings hold up in a larger study, there would be limitations, Pardini adds. “In a practical sense, there are just too many ways an offender could get around having an accurate representation of his brain activity taken,” he said. For example, if an offender moves his head while inside the scanner, that would render the scan unreadable. Even more subtle strategies, such as thinking about something unrelated to the task, or making mistakes on purpose, could also thwart the test.

Kiehl isn’t convinced either that this type of fMRI test will ever prove useful for assessing the risk to society posed by individual criminals. But his group is collecting more data — lots more — as part of a much larger study in the New Mexico state prisons. “We’ve scanned 3,000 inmates,” he said. “This is just the first 100.”

Kiehl hopes this work will point to new strategies for reducing criminal behavior. If low activity in the anterior cingulate does in fact turn out to be a reliable predictor of recidivism, perhaps therapies that boost activity in this region would improve impulse control and prevent future crimes, Kiehl says. He admits it’s speculative, but his group is already thinking up experiments to test the idea. ”Cognitive exercises is where we’ll start,” he said. “But I wouldn’t rule out pharmaceuticals.”

A quem serve negar o impacto PCC? (Caros Amigos)

Publicado em Sexta, 24 Agosto 2012 14:26

Por Daniel Hirata, Adalton Marques, Gabriel Feltran e Karina Biondi

“Ao ser citada em um relatório com uma redução que posiciona a cidade abaixo da linha imaginária do índice “epidêmico”, as políticas governamentais de segurança ganham enorme respaldo nacional e internacional”

As taxas de homicídios são atualmente o grande parâmetro de avaliação das políticas de segurança em todo o mundo. Assim como a cotação do dólar e a taxa de juros para a política monetária, as flutuações das taxas de homicídios vêm sendo parâmetro de avaliação da gestão pública: cidades que conseguem reduções expressivas são vistas como modelos de ”boas práticas” a replicar. São Paulo foi incluída recentemente, no relatório de 2011 do Onudoc (United Nations Office on Drugs and Crime), como um ‘case’ na redução da taxa de homicídios em comparação com outras cidades latino americanas e brasileiras. Ao ser citada em um relatório desse tipo, sobretudo com uma redução que posiciona a cidade abaixo da linha imaginária do que é considerado um índice “epidêmico”, as políticas governamentais de segurança ganham enorme respaldo nacional e internacional.

Crédito Eleitoral

Sabe-se bem como esse ganho foi capitalizado rapidamente pelo governo paulista durante a última década. Contudo, esse crédito eleitoral e, acima de tudo, político-administrativo, não foi usufruído sem que, bem longe das razões governamentais, se constituísse um lastro que sustenta outra história acerca da redução das taxas de homicídios.

Nossas pesquisas voltaram os olhos precisamente para esta versão, levando a sério aquilo que se insiste em considerar anômico: o que dizem presos e moradores das periferias de São Paulo sobre a violência, a segurança e os homicídios. Nessa mesma direção, desde 2005, temos registrado entre eles relatos da política de “paz” do PCC (Primeiro Comando da Capital) em prisões e “quebradas”, e a importância dos seus “debates” na redução dos homicídios por ali. Sabe-se que, nesses territórios, desde a primeira metade dos anos 2000, “não se pode mais matar” sem o aval do “Comando”.

“A emergência dessa forma de regulação torna complexa a deslegitimação da “segurança pública” nas periferias, onde a repressão é sua única face: seja pela política de encarceramento em massa, pela militarização da gestão pública ou pelos achaques a que seus moradores são constantemente submetidos”

A emergência dessa forma de regulação torna complexa a deslegitimação da “segurança pública” nas periferias, onde a repressão é sua única face: seja pela política de encarceramento em massa, pela militarização da gestão pública ou pelos achaques a que seus moradores são constantemente submetidos. O impacto dessas políticas nas estatísticas é evidente, embora silenciado ativamente e sistematicamente por governos e imprensa e rejeitado por ‘think tanks’ que disputam o tema segurança pública, assim como fora praticamente desconsiderado em nossas universidades há poucos anos.

Fator PCC

Há uma razoável concordância entre os especialistas de que a violência e o homicídio são fenômenos históricos e multidimensionais. Nesse sentido, é claro que o PCC não é a única causa dessa redução. Mas digamos francamente: é um absurdo fingir que o PCC não é central para compreender esse fenômeno. Em São Paulo, há muito mais mistérios por detrás da redução dos homicídios do que supõe nossa vã criminologia. Mas, principalmente, há muito mais evidências ofuscadas sob o holofote das suposições.

Afirmamos, portanto, que os sucessivos governos do PSDB em São Paulo não são os únicos fiadores da redução da taxa de homicídios no Estado, nem mesmo os majoritários. E, ao invés de atribuirmos a fiança majoritária ao PCC, preferimos falar de sua centralidade, da importância inegável de sua política de “paz entre os ladrões” para a queda dos homicídios em São Paulo.


Nossa aferição não é sociométrica; antes, se trata de uma problematização etnográfica. Além do que, sabe-se que os critérios de construção dessas medidas são polêmicos e cheios de controvérsias. No Rio de Janeiro, por exemplo, onde esse tipo de controvérsia emerge de forma mais visível publicamente, uma pesquisa recente do Núcleo de Estudos da Cidadania, Conflito e Violência Urbana (NECVU) sobre os “autos de resistência” problematiza a leitura fácil sobre as taxas de homicídio justamente quando volta a atenção para onde os olhos dos governos insistem em não olhar: a atuação das polícias.

“Ao largo das condecorações fáceis dos responsáveis pela miraculosa queda dos homicídios, preferimos seguir os rastros das “guerras” que continuam a aterrorizar a periferia – ainda que suas manifestações mais espetaculares tenham se tornado cíclicas”

Ao largo das condecorações fáceis dos responsáveis pela miraculosa queda dos homicídios, preferimos seguir os rastros das “guerras” (categoria usada por “ladrões” e por policiais) que continuam a aterrorizar a periferia – ainda que suas manifestações mais espetaculares tenham se tornado cíclicas. É notório em nossas pesquisas que parte das dinâmicas que produzem mortes na cidade estão relacionadas aos jogos de poder entre coletivos criminais e corporações policiais, em suas atividades oficiais e extra oficiais. A atual intensificação do caráter repressivo e militar das políticas de segurança não apenas acentua a “lógica da guerra” no controle oficial do crime, como também aumenta os custos e os conflitos operantes nos mercados extra oficiais de proteção, cujos desfechos letais são muito frequentes no cotidiano dos alvos preferenciais desse controle.

Equilíbrios Instáveis

Neste momento, ao contrário do discurso oficial que insiste em negar a existência do PCC e exibe a polícia de São Paulo como a mais eficaz do Brasil, a cidade presencia diversos assassinatos em todas as regiões da Grande São Paulo. O fato é que tanto a atuação do PCC como a das polícias são feitas a partir de equilíbrios instáveis, construídos pelas suas heterogeneidades internas e pelas relações entre ambos. Quando algo desestabiliza esse encadeamento sensível os acordos se rompem e os ciclos de mortes são detonados sem que nem mesmo seus participantes consigam identificar os autores: guerras estancadas começam a correr subterraneamente, acertos adiados passam a acontecer entre grupos com interesses conflitantes sem declaração aberta, acordos são suspensos secretamente, de modo que sempre é possível culpar o “outro lado” pela morte que não se pode nomear o autor nem as razões.

Enquanto não escancararmos com pesquisa rigorosa a caixa de pandora dessas relações para ao menos dar início ao debate, continuaremos sem qualquer resposta pública, digna, para as dezenas de assassinatos que voltaram a marcar a Grande São Paulo, bem como sem uma explicação satisfatória que correlacione a política de “pacificação” do PCC com os surtos de combate entre Estado e crime.

Daniel Hirata é pesquisador do Núcleo de Estudos da Cidadania, Conflito e Violência Urbana (NECVU) da UFRJ; Adalton Marques é doutorando do Programa de Pós-Graduação em Antropologia Social da UFSCar (PPGAS-UFSCar); Gabriel Feltran é sociólogo, docente da UFSCar e membro do Centro de Estudos da Metrópole (CEM) da universidade e Karina Biondi é doutoranda do PPGAS-UFSCar



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Mães de Maio pede ação de Dilma para conter ataques em SP

Concerns Over Accuracy of Tools to Predict Risk of Repeat Offending (Science Daily)

ScienceDaily (July 24, 2012) — Use of risk assessment instruments to predict violence and antisocial behavior in 73 samples involving 24,827 people: systematic review and meta-analysis

Tools designed to predict an individual’s risk of repeat offending are not sufficient on their own to inform sentencing and release or discharge decisions, concludes a study published on the British Medical Journal website.

Although they appear to identify low risk individuals with high levels of accuracy, the authors say “their use as sole determinants of detention, sentencing, and release is not supported by the current evidence.”

Risk assessment tools are widely used in psychiatric hospitals and criminal justice systems around the world to help predict violent behavior and inform sentencing and release decisions. Yet their predictive accuracy remains uncertain and expert opinion is divided.

So an international research team, led by Seena Fazel at the University of Oxford, set out to investigate the predictive validity of tools commonly used to assess the risk of violence, sexual, and criminal behavior.

They analyzed risk assessments conducted on 24,827 people from 13 countries including the UK and the US. Of these, 5,879 (24%) offended over an average of 50 months.

Differences in study quality were taken into account to identify and minimize bias.

Their results show that risk assessment tools produce high rates of false positives (individuals wrongly identified as being at high risk of repeat offending) and predictive accuracy at around chance levels when identifying risky persons. For example, 41% of individuals judged to be at moderate or high risk by violence risk assessment tools went on to violently offend, while 23% of those judged to be at moderate or high risk by sexual risk assessment tools went on to sexually offend.

Of those judged to be at moderate or high risk of committing any offense, just over half (52%) did. However, of those predicted not to violently offend, 91% did not, suggesting that these tools are more effective at screening out individuals at low risk of future offending.

Factors such as gender, ethnicity, age or type of tool used did not appear to be associated with differences in predictive accuracy.

Although risk assessment tools are widely used in clinical and criminal justice settings, their predictive accuracy varies depending on how they are used, say the authors.

“Our review would suggest that risk assessment tools, in their current form, can only be used to roughly classify individuals at the group level, not to safely determine criminal prognosis in an individual case,” they conclude. The extent to which these instruments improve clinical outcomes and reduce repeat offending needs further research, they add.