Tag Archives: crime

police officers accidentally film themselves planting evidence

According to the Intercept,

Last month, the city public defender’s office discovered body camera footage showing a local cop placing a bag of heroin in a pile of a trash in an alley. The cop, unaware he was being filmed, walked out of the alley, “turned on” his camera, and went back to “find” the drugs. The cop then arrested a man for the heroin, placed him in jail. The man, who couldn’t afford to post the $50,000 bail, languished there for seven months. He was finally released two weeks ago, after the public defender’s office sent the video to the state attorney.

So, I think I support the body cameras, I don’t really see why honest police officers wouldn’t support them too. Maybe they shouldn’t even have an “off” button.

eyes on the street

A group at the University of Pennsylvania looked for statistical evidence that “eyes on the street” are a deterrent to crime. The results are a bit puzzling, as real world data often can be.


Statistical analyses of urban environments have been recently improved through publicly available high resolution data and mapping technologies that have adopted across industries. These technologies allow us to create metrics to empirically investigate urban design principles of the past half-century. Philadelphia is an interesting case study for this work, with its rapid urban development and population increase in the last decade. We focus on features of what urban planners call vibrancy: measures of positive, healthy activity or energy in an area. Historically, vibrancy has been very challenging to measure empirically. We explore the association between safety (violent and non-violent crime) and features of local neighborhood vibrancy such as population, economic measures and land use zoning. Despite rhetoric about the negative effects of population density in the 1960s and 70s, we find very little association between crime and population density. Measures based on land use zoning are not an adequate description of local vibrancy and so we construct a database and set of measures of business activity in each neighborhood. We employ several matching analyses within census block groups to explore the relationship between neighborhood vibrancy and safety at a higher resolution. We fi nd that neighborhoods with more vacancy have higher crime but within neighborhoods, crimes tend not to be located near vacant properties. We also find that more crimes occur near business locations but businesses that are active (open) for longer periods are associated with fewer crimes.

This is particularly fascinating to me because I live my life in the middle of this particular data set and am part of it. So it is very interesting to compare what the data seem to be saying with my own experiences and impressions.

The lack of correlation between population density and crime is not surprising. Two neighborhoods with identical density can be drastically different. The correlation between poverty and crime is not surprising – people who are not succeeding in the formal economy and who are not mobile turn to the informal economy, in other words drug dealing, loan sharking and other illegal ways of trying to earn an income. If they are successful at earning an income, they tend to have a lot of cash around, and other people who know about the cash will take advantage of them, knowing they will not go to the police. Other than going to the police, the remaining options are to be taken advantage of repeatedly, or to retaliate. This is how violence escalates, I believe, and it goes hand in hand with development of a culture that tolerates and even celebrates violence, in a never-ending feedback loop.

The puzzling part comes when they try to drill down and look at explanatory factors at a very fine spatial scale. They found a correlation between crime and mixed use zoning, which appears to contradict the idea that eyes on the street around the clock will help to deter crime. And they found more crime around businesses like cafes, restaurants, bars and retail shops. They found that longer open hours seemed to have some deterrent effect on crime relative to shorter open hours.

I think they have made an excellent effort to do this, and I am not sure it can be done a lot better, but I will point out one idea I have. They talk about some limitations and nuances of their data, but one they do not mention is the idea that they are looking at reported crimes, most likely police reports or 911 calls. It could be that business owners, staff and patrons are much more likely to call 911 and report a crime than are residential neighbors. The business staff and patrons may see this as being in the economic interest, increasing the safety of their families, and the (alleged) criminals they are reporting are generally strangers. In quieter all-residential neighborhoods, people may not observe as many of the crimes that do occur (fewer “eyes on the street”), they may prefer not to report crimes either through a sense of loyalty to one’s neighbors, minding one’s own business, quid pro quo, or in some cases a fear of retaliation. There is also the factor of some demographic groups trusting the police more than others, although the authors’ statistical attempts to control for demographics may tend to factor this out.


Richard Berk

Here’s a Bloomberg article on Richard Berk, a statistician at the University of Pennsylvania whose algorithms are used for parole, probation, and sentencing decisions.

Risk scores, generated by algorithms, are an increasingly common factor in sentencing. Computers crunch data—arrests, type of crime committed, and demographic information—and a risk rating is generated. The idea is to create a guide that’s less likely to be subject to unconscious biases, the mood of a judge, or other human shortcomings. Similar tools are used to decide which blocks police officers should patrol, where to put inmates in prison, and who to let out on parole. Supporters of these tools claim they’ll help solve historical inequities, but their critics say they have the potential to aggravate them, by hiding old prejudices under the veneer of computerized precision. Some people see them as a sterilized version of what brought protesters into the streets at Black Lives Matter rallies…


slot machines and pseudo-random numbers

Russian hackers have been able to beat a certain brand of slot machine by buying old models, studying their coding, and figuring out the pattern of random numbers they generate. From Wired:

But as the “pseudo” in the name suggests, the numbers aren’t truly random. Because human beings create them using coded instructions, PRNGs can’t help but be a bit deterministic. (A true random number generator must be rooted in a phenomenon that is not manmade, such as radioactive decay.) PRNGs take an initial number, known as a seed, and then mash it together with various hidden and shifting inputs—the time from a machine’s internal clock, for example—in order to produce a result that appears impossible to forecast. But if hackers can identify the various ingredients in that mathematical stew, they can potentially predict a PRNG’s output. That process of reverse engineering becomes much easier, of course, when a hacker has physical access to a slot machine’s innards.

Knowing the secret arithmetic that a slot machine uses to create pseudorandom results isn’t enough to help hackers, though. That’s because the inputs for a PRNG vary depending on the temporal state of each machine. The seeds are different at different times, for example, as is the data culled from the internal clocks. So even if they understand how a machine’s PRNG functions, hackers would also have to analyze the machine’s gameplay to discern its pattern…

… the operatives use their phones to record about two dozen spins on a game they aim to cheat. They upload that footage to a technical staff in St. Petersburg, who analyze the video and calculate the machine’s pattern based on what they know about the model’s pseudorandom number generator. Finally, the St. Petersburg team transmits a list of timing markers to a custom app on the operative’s phone; those markers cause the handset to vibrate roughly 0.25 seconds before the operative should press the spin button.

lead, crime and teen pregnancy

Leaded gasoline peaked around the year I was born, and both crime and teen pregnancy peaked while I was a teenager. I managed to steer clear of these two things (or maybe I left no evidence in either case…), but maybe I would have been the next Einstein if it weren’t for lead, we’ll never know.

Lead Exposure and Behavior: Effects on Antisocial and Risky Behavior among Children and Adolescents Jessica Wolpaw Reyes NBER Working Paper No. 20366 August 2014

It is well known that exposure to lead has numerous adverse effects on behavior and development. Using data on two cohorts of children from the NLSY, this paper investigates the effect of early childhood lead exposure on behavior problems from childhood through early adulthood. I find large negative consequences of early childhood lead exposure, in the form of an unfolding series of adverse behavioral outcomes: behavior problems as a child, pregnancy and aggression as a teen, and criminal behavior as a young adult. At the levels of lead that were the norm in United States until the late 1980s, estimated elasticities of these behaviors with respect to lead range between 0.1 and 1.0.

Maybe we learned our lesson with lead and mercury and have moved on. Or maybe something as bad or worse is hiding in plain site in our consumer products and we just haven’t figured it out yet.

Just for the archives, here is a key 2000 study by Rick Nevin on the subject: How Lead Exposure Relates to Temporal Changes in IQ, Violent Crime, and Unwed Pregnancy.

This study compares changes in children’s blood lead levels in the United States with subsequent changes in IQ, based on norm comparisons for the Cognitive Abilities Test (CogAT) given to representative national samples of children in 1984 and 1992. The CogAT norm comparisons indicate shifts in IQ levels consistent with the blood lead to IQ relationship reported by an earlier study and population shifts in average blood lead for children under age 6 between 1976 and 1991. The CogAT norm comparisons also support studies indicating that the IQ to blood lead slope may increase at lower blood lead levels. Furthermore, long-term trends in population exposure to gasoline lead were found to be remarkably consistent with subsequent changes in violent crime and unwed pregnancy. Long-term trends in paint and gasoline lead exposure are also strongly associated with subsequent trends in murder rates going back to 1900. The Andings on violent crime and unwed pregnancy are consistent with published data describing the relationship between IQ and social behavior. The Andings with respect to violent crime are also consistent with studies indicating that children with higher bone lead tend to display more aggressive and delinquent behavior. This analysis demonstrates that widespread exposure to lead is likely to have profound implications for a wide array of socially undesirable outcomes.

Trump and organized crime

Here’s a long article on BillMoyers.com, with links to a lot of other articles, about Donald Trump’s alleged mob links.

While there are some financial subjects on which the media has dared to grill the billionaire — ABC’s George Stephanopoulos last month got Trump to deliver a blunt “no” when he asked about the Republican nominee-apparent’s repeated refusal to release his recent tax returns, something every other recent presidential candidate has done — there has been remarkably little interest shown in some of Trump’s less-than-savory connections.

One of the exceptions is Johnston, who, over the course of 27 years, has had ample occasion to pay attention to Trump’s finances and mob ties. He was not the first investigative reporter to do so. In 1992, Johnston favorably reviewed the longtime Village Voice reporter Wayne Barrett’s highly unauthorized biography, Trump: The Deals and the Downfall, which, in Johnston’s words, “asserts that throughout his adult life, Donald Trump has done business with major organized-crime figures and performed favors for their associates.” As Barrett said not long after Trump declared for the presidency last year, Trump’s life “intertwines with the underworld.” Barrett updates his treatment of Trump in a new digital edition calledTrump, The Greatest Show on Earth: The Deals, the Downfall, the Reinvention

Beyond ABC News’ Ross, TV has been even less eager to press inquires about Trump’s history of relations with organized crime. Nor have questions of Trump’s mob ties been much explored in other major news outlets. A notable exception: Johnston, who, in Politico last month, raised yet more questions. One was why Trump relied on ready-mix reinforced concrete construction (mob-controlled) to build his eponymous Fifth Avenue tower and subsequent New York buildings, although steel girders were the usual choice. Another was why, when seeking a license to build casinos in Atlantic City, Trump received special treatment from New Jersey gaming investigators, “Thanks in part to the laxity of New Jersey gaming investigators,” Johnston wrote, “Trump has never had to address his dealings with mobsters and swindlers head-on.” Wayne Barrett calls Trump Tower “a monument to the mob.” He writes of the “sweetheart deals” that delivered the concrete, and the special tax abatements that have continued to roll in for Trump. There, so far as the public is concerned, the matter has rested. Why do the major media, ordinarily eager to fight for their own angles on big stories, lag? Why do the dogs not bark and the chambers not echo?

more on Alice Goffman

Recently I was talking about how much I enjoyed On The Run: Fugitive Life in an American City. I knew there was some controversy over the book, but I didn’t realize how much. I actually assumed she was a journalist, but it turns out she is a sociologist and some sociologists think they are not supposed to write books like that. (Later though, the article says that journalists have criticized her and sociologists have defended her, so I am a little confused there.) I don’t think I know any sociologists, or a lot about them. Once I knew an anthropologist, and I asked him how he was different from a sociologist, but he just laughed and never answered my question. The problem, some say, is that she got too close to her subjects, was too quick to repeat everything they told her, and reinforced stereotypes. On the last, I think that is completely false. If anything, she does a lot to humanize and find redeeming qualities in people who do some risky and violent things. As for the way she got personally involved with her subjects, that is what makes the story so engaging. I think ultimately it is a story told from a certain point of view, and you have to keep that point of view in mind almost as though you were reading a novel. Whether that is good academic sociology or not I wouldn’t know, but I enjoyed the book.

By the way, Alice Goffman did a TED talk which is more or less a summary of the book.

Jeffrey Sachs vs. the CIA

Jeffrey Sachs does not like the CIA.

The public has never really been told the true history of Osama bin Laden, Al Qaeda, or the rise of ISIS in Iraq and Syria. Starting in 1979, the CIA mobilized, recruited, trained, and armed Sunni young men to fight the Soviet Union in Afghanistan. The CIA recruited widely from Muslim populations (including in Europe) to form the Mujahideen, a multinational Sunni fighting force mobilized to oust the Soviet infidel from Afghanistan…

By promoting the core vision of a jihad to defend the lands of Islam (Dar al-Islam) from outsiders, the CIA produced a hardened fighting force of thousands of young men displaced from their homes and stoked for battle. It is this initial fighting force – and the ideology that motivated it – that today still forms the basis of the Sunni jihadist insurgencies, including ISIS. While the jihadists’ original target was the Soviet Union, today the “infidel” includes the US, Europe (notably France and the United Kingdom), and Russia…

Blowback against the US began in 1990 with the first Gulf War, when the US created and expanded its military bases in the Dar al-Islam, most notably in Saudi Arabia, the home of Islam’s founding and holiest sites. This expanded US military presence was anathema to the core jihadist ideology that the CIA had done so much to foster.

I wouldn’t go so far as to say “violence is never the answer”. There are always bullies and thugs out there who will take advantage of you if they know you won’t defend yourself. But in the longer term, I think the answer to violence is always to find a way to de-escalate. People, particularly young men, need economic opportunity, and their legitimate grievances need to be identified and addressed. These are the root causes of most violence. After you figure out these two things, you can also think about how to alter any cultural norms that make violence seem okay, and limiting access to weapons. Finally, you can round up the remaining handful of hard core thugs and bullies if there are still some out there. All this is as true on the streets of an American city as it is in the Middle East. Note how both the “war on drugs” and the “war on terror” have gone about this in exactly the reverse order from what I just suggested – start with a violent military or law enforcement approach targeting a whole class of people, go after the weapons, and blame the culture. All this is great for business if you are part of the military-industrial or police-court-prison-industrial complex. If we address the root causes – legitimate grievances and lack of economic opportunity – at all, we tend to give them the least attention and funding.