Fingerprinting to solve crimes: not as robust as you think

Jamie Walvisch, Monash University

Police have used fingerprint evidence to catch and convict criminals for more than 100 years. It’s a commonly used technique in Australia: more than 10,000 fingerprint matches were made in Victoria alone last year.

But in a recent report, the American Association for the Advancement of Science has questioned the scientific validity of fingerprint analysis.

The report is a reminder that although fingerprinting is an essential tool for investigating crime, it’s not infallible. We need to minimise the inappropriate application of the “science” of fingerprinting, and reduce repeats of miscarriages of justice linked to fingerprint analysis that have already occurred.

Read more: Forensic evidence largely not supported by sound science – now what?

Most notoriously, Brandon Mayfield, an American lawyer, was wrongly linked by four fingerprint experts to the 2004 Madrid train bombing. He was arrested and detained for two weeks, before investigators realised that an Algerian man, Ouhnane Daoud, was the real source of the print.

How does fingerprint examination work?

Everybody’s fingers, palms and soles have “friction ridges” on them. These ridges occur in patterns (such as arches and loops) that contain specific features (for example, ridge endings and dots).

Fingerprint examiners use these patterns and features to compare an unknown (or “latent”) print with a known print, to determine if they may have come from the same person.

In Australia, police use the National Automated Fingerprint Identification System – a database with more than 2.6 million sets of fingerprints – to narrow down the field of fingerprints to compare. But the final decision about whether there is a “match” is made by a person.

A 2010 report, published by the US National Institute of Justice, concluded that automated systems were significantly less accurate than well-trained examiners at making comparisons between latent and known prints.

Problems with the underlying science

Until the mid-2000s, little scientific research had been done on most forensic disciplines, including fingerprinting. This lack of research became widely publicised in 2009, when the US National Research Council published a landmark report on the forensic sciences.

It found that the only forensic method that had been rigorously validated was nuclear DNA analysis. All other forensic sciences – including fingerprinting – lacked a proper scientific foundation.

Read more: From the crime scene to the courtroom: the journey of a DNA sample

When examining this issue again in 2016, the President’s Council of Advisors on Science and Technology (PCAST) in the US found that only two properly designed studies of latent fingerprint analysis had been conducted. These both found the rate of false matches (known as “false positives”) to be very high: 1 in 18 and 1 in 30.

One of the main reasons for these high error rates is that fingerprint analysis involves human judgement, and relies on a methodology (known as “ACE-V”) that is not sufficient to ensure the accuracy and reliability of an examiner’s conclusions. This means there is no guarantee that two different examiners who follow its steps will reach the same result.

Recent improvements

Since the National Research Council report was released, scientists have worked hard to prove that fingerprint examination is scientific.

Research has now convincingly established that the ridge patterns on fingers vary greatly among individuals, and that there is little variation in a person’s fingerprints over time. This provides a scientific basis for using fingerprints to distinguish individuals, even identical twins.

But there is still no scientific basis for concluding that a print must have been left by a specific person, or even for estimating the number of people who might be the source of a print.

The most that can be said is that two prints have many corresponding features, with no differences that would indicate they were made by different fingers. It may also be possible for an examiner to say that the set of features found in the prints is unusual.

Cognitive bias

Because fingerprint analysis depends heavily on human judgement, an examiner’s conclusions may be improperly influenced by non-scientific factors, such as irrelevant contextual information.

Read more: Explainer: how law enforcement decodes your photos

This phenomenon, which is known as “cognitive bias”, has been demonstrated in various studies.

In one study, five fingerprint experts were told they were comparing Brandon Mayfield’s fingerprint with the fingerprint found in Madrid. They were asked whether they would also have (wrongly) found a match.

In reality, the experts were given fingerprints from a different case they had personally found to match years earlier, in the normal course of their casework. Four of the five experts changed their opinion. This was seen to be due to their expectation that the fingerprints did not match.

Another study found that fingerprint examiners can be improperly influenced by the use of automated fingerprint identification systems, which provide ordered lists of the most likely matches.

The study found that examiners are more likely to wrongly identify one of the prints near the top of the list as a match, and to fail to make correct identifications if the print is down low on the list.

Implications

While these reports and studies indicate a need for caution when relying on fingerprint examinations, they do not mean that police should stop using fingerprints.

Fingerprinting is an essential tool for investigating crime, and should continue to be used for this purpose. But steps need to be taken to limit the likelihood of future miscarriages of justice.

Everyone in the system has a role to play. Scientists need to conduct further research under realistic conditions.

Police forces must take steps to minimise the risks of cognitive bias. For example, they should use context management procedures to avoid exposing examiners to unnecessary contextual information.

Lawyers and judges must make sure that only scientifically valid opinions are given in court, and that the value of fingerprint evidence is not overstated. Fingerprint examiners should make it clear that they are expressing an opinion and not a fact.

And everyone should acknowledge that errors do occur in fingerprinting analysis, and have happened in the past.

Jamie Walvisch, Lecturer, Monash University

This article was originally published on The Conversation. Read the original article.

Parents of teenage daughters more likely to divorce: study

Jan Kabatek, University of Melbourne and David C. Ribar, University of Melbourne

Sullen exchanges and broken curfews are part of life for parents of teenagers, but could this period also be a stress-test for parents’ marriages?

Our new data analysis finds parents with daughters are slightly more likely to separate than those with sons, but only during the teenage years. And it’s the strained relationship between parents and their daughters that might bring a couple to the breaking point.

Our working paper studied more than 2 million marriages in The Netherlands over ten years and shows that divorce risks increase with children’s ages until they reach adulthood – with parents of teenage daughters at greater risk. However, this risk disappears in cases where the fathers themselves grew up with a sister.

Evidence on daughters and divorce

Previous research examined the link between marital strains and children’s gender, but it’s always been a challenging area.

Several studies in the US have found that parents with first-born girls are slightly more likely to divorce than parents with first-born boys. However, other US studies have challenged this finding, and until now, there was no evidence from other developed countries showing that daughters strained marriages.

Our research examined registry data from The Netherlands. Compared with datasets used in most previous studies, Dutch records are very comprehensive. They allow us to look at exact dates of weddings, births, and divorces, and delve deeper than previous studies, which relied on self-reports and people’s recollections.

More importantly, the data allow us to examine the gender of couples’ children, and just how long after their birth the couples separated.

We found that up until the age of 12, there are no differences between the divorce risks faced by parents of boys and girls. However, between the ages 13 and 18, parents of first-born girls divorce more than parents of first-born boys.

The odds of divorce within this period are 10.7% for parents of boys, and 11.3% for parents of girls. In relative terms, this means that parents with teenage daughters face 5% higher risks of divorce than parents with teenage sons.

The effect peaks at age 15, when the risk faced by parents with daughters is almost 10% higher than the risk faced by parents with sons. In the following years, the differences narrow again, and they disappear once the child turns 19. A similar pattern is also found among second-born and subsequent children.

Although no causal link could be established from the Dutch data, the higher divorce rates might be explained by strained relationships between young women and their parents.

The increased odds of divorce from teenage daughters aren’t unique to Dutch married couples – we find the same association for Dutch couples in de facto relationships, and for married couples in the US. In fact, we find that both of these groups face considerably higher increases of divorce odds from teenage daughters, compared to Dutch married couples.

Attitudes to gender

Social scientists suggest there are several reasons why daughters might raise divorce risks. One well-established theory says that some parents have cultural or social preferences for sons.

Another theory assumes that boys are more vulnerable and their need of a male role model makes fathers more committed to the marriage. There is also a sex-selection theory which postulates that mothers whose marriages are more stressful may be more likely to give birth to a baby girl.

However, we do not find empirical evidence in support of any of these theories.

Instead, our findings suggest the higher divorce rates are explained by strains in the relationships between some parents and their teenage daughters, possibly stemming from differences in attitudes toward gender roles.

This explanation is backed by the separate analysis of a large survey of Dutch households, which asked families about their relationships and opinions regarding marriage, gender and parenting.

Parents of teenage daughters disagreed more about the way they should raise their children, and expressed more positive attitudes towards divorce. They were also less satisfied with the quality of their family relationships.

Teenage daughters, in turn, reported worse relationships with their fathers, though not with their mothers.

Growing up with a sister

We took our research a step further – we looked at the father’s family history to investigate the link between fathers and their daughters. Specifically, we compared the divorce risks faced by fathers who grew up with sisters, and fathers who did not.

Our hypothesis is that the fathers who had more experience relating to teenage girls (via their sisters) would experience fewer relationship strains with their teenage daughters. This could occur because fathers with sisters may hold more egalitarian attitudes toward gender roles, or because they have a better understanding of teenage girls and their family interactions.

And in line with this reasoning, we found that the fathers who grew up with sisters did not face any increase in divorce risks from teenage daughters – the pattern only appeared among fathers who grew up without sisters.

We also looked at other family characteristics that could indicate differences between the gender-role attitudes held by parents and their daughters, such as the ages or immigration background of the couple. Here, we found that the parents who are likely to hold more traditional attitudes toward gender roles experienced higher increases of divorce odds from teenage daughters.

Destined for divorce?

Despite their relative significance during the teenage years, the difference in the divorce risks faced by families with boys and girls remains modest over the child’s lifetime.

By the time their first-born children reached age 25, 311 out of every 1,000 Dutch couples with daughters had divorced compared to 307 of every 1,000 with sons – a difference of only four divorces per 1,000 couples.

And our finding of a null effect among fathers who grew up with sisters also shows that the association between a child’s gender and divorce risk is not universal.

However, our results do point to serious strains between some parents and their teenage daughters, and help us understand the factors contributing to family breakdown.

The results also suggest these risks can be reduced if the parents of teenage daughters adopt more egalitarian attitudes towards gender roles and a greater understanding of how conflicts could come up.

Struggles with teenagers will still happen, but better preparation and knowledge of the wants and needs of their teenage daughters could reduce the strain between partners.

This article was co-published with Pursuit.

Jan Kabatek, Research Fellow, Melbourne Institute of Applied Economic and Social Research, University of Melbourne and David C. Ribar, Professorial Research Fellow, University of Melbourne

This article was originally published on The Conversation. Read the original article.

Revenge porn laws may not be capturing the right people

Terry Goldsworthy

Australia is moving quickly towards creating laws to deal with the perceived menace of revenge porn. Both the Australian Capital Territory and New South Wales have recently introduced specific laws, bringing them into line with Victoria, South Australia and Western Australia.

But the creation of new offences may not be the panacea it is intended to be. Instead, we should focus our efforts on overcoming investigative challenges and implementing crime prevention strategies in a more practical approach.

What do we mean by revenge porn?

When it first became an issue, “revenge porn” referred to the unauthorised public release of intimate images that arose from a relationship.

However, the term is now used to capture the illegal distribution of intimate images, regardless of the relationship status between offender and victim. It also includes the use of faked nude images. Recent revenge porn offences have featured the anonymous dumping of mass images of multiple victims on the internet.

It has been argued that the act of revenge porn should be considered an extension of sexual assault, given the potential impact on victims. Indeed, the eSafety Commissioner’s office identified that:

… non-consensual sharing of private sexual images can be a form of family violence or sexual abuse.

In 2014, Israel made revenge porn a crime by drafting a new law stipulating that those found guilty of posting such content will be prosecuted as sexual offenders.

However, there are differences between those victimised by physical sexual assault and revenge porn.

ABS data from 2016 show that one in five victims of sexual assault are male. Yet recent Australian research has shown that men and women are equally likely to report being a victim of image-based abuse. The US research showed 3% of male and 5% of female internet users has suffered non-consensual image sharing.

The extent of revenge porn

A search of the Factiva media search engine using the term “revenge porn” shows that in 2012 there were eight stories in the international media. Just three years later, there were 3,176.

The rise of revenge porn has been facilitated by our ability to create content and distribute it. This ability has been multiplied by professional facilitators and technology, such as porn sites hosting, which can reach much larger audiences. In 2014, at least 3,000 porn websites around the world featured the revenge genre.

A 2016 study by the US Data and Research Institute showed one in 25 online Americans has been a victim of someone posting, or threatening to post, nearly nude or nude images of them without their permission. In Australia, research has shown 23% of those aged 16 to 45 have been subjected to image-based abuse.

The new laws

Australia now has more states and territories with specific revenge porn laws than those without. Queensland, Tasmania and the NT remain without such laws.

This move to specific laws reflects overseas trends. In the US, 38 states (plus Washington DC) have criminal laws against revenge porn, with legislation pending in additional states. The UK, Canada, New Zealand and Japan are just some of the countries to adopt specific revenge porn laws. Many of these laws extend revenge porn from distribution of an intimate image to include the creation of, and threats to distribute, those images.

In 2016, 206 people were prosecuted under UK laws for revenge porn.

Data obtained from the Victorian Crime Statistics Agency shows that since the implementation of revenge porn laws in 2015, until July 2017, there have been 415 reports of offences of threatening to or intentionally distributing an intimate image. Some 13% of those cases remain unsolved and 117 people have been charged under those laws.

Are existing laws sufficient?

In Australia, the current Commonwealth law to deal with revenge porn covers using a carriage service to menace, harass or cause offence. It relies on the prosecution showing that the effect of releasing the image is that a reasonable person would regard it as being menacing, harassing or offensive.

Women’s Minister Michaelia Cash has noted:

Under this offence, there have been a number of successful prosecutions for revenge porn.

One example is the Queensland woman who was in a relationship with a married man. The relationship ended and the man returned to his wife, after which he was instructed to destroy intimate images of the victim. The man did not, and his wife posted them on Facebook. The wife was charged under the Commonwealth legislation and convicted.

WA has limited revenge porn laws for domestic relationships, using them as part of family violence restraining orders.

The WA attorney-general, Michael Mischin, argued the Victorian laws were targeting the wrong offenders:

So it’s stupidity, naivety and immaturity rather than criminality and that’s not quite what we’re driving at.

The Victorian Crime Statistics Agency data show that between June 2015 and June 2017, 23% of male offenders were aged between 10-19 years of age. Females made up 13% of offenders.

But not all states are rushing to implement specific laws, given that existing laws are adequate and those being targeted by the laws may not be those intended.

Queensland Attorney-General Yvette D’Ath is still examining whether existing laws needed to be strengthened.

Where to from here?

There is insufficient evidence from the current laws’ success rates to justify a move to specific laws. There has also been a failure to show how these new offences are effective in tackling other deficiencies identified in responses to revenge porn offences.

These issues include ensuring we have effective victim responses to revenge porn, such as strategies to increase ease of reporting and reduce under-reporting.

A lack of specialisation in policing responses has also been identified in various government inquiries. Additional training for police is needed to deal with complex investigations that can involve cross-jurisdictional and transnational issues.

The role of social media platforms will also be crucial to an effective response. We must differentiate between legitimate crime prevention strategies and victim-blaming in what can be a highly emotive area.

So, the upshot is that we need to give existing laws more time to see if they are effective before we implement new ones, and we must ensure any new laws are targeting the intended offenders.

Terry Goldsworthy, Assistant Professor in Criminology

This article was originally published on The Conversation. Read the original article.