Police Data

 The helpful folks at the city recently provided me with the RIPA data through August, so it's a good time to check in on the State of Los Altos Policing for the first half of the year. It's been a fairly quiet summer on the police policy front, with a few high-visibility arrests using ALPRs, and discussion going on about purchasing drones for the police. Here's what we are seeing on the data front -- after all, this is a data blog! RIPA Stops As you all know by now, every police department in California is required to collect data on every single stop that they make. This data, suitably anonymized, is then public. You can get this by submitting a public records request to the City; I've also put it in the github repo, along with all the analysis code, if you'd like to look at it yourself. Here are the stops per month since Los Altos started collecting RIPA data. As you can see, the vast majority of stops are for traffic violations. There are lots of ways you might ...

Despite guidance from California Attorney General Rob Bonta, quite a few California police departments are sharing automated license plate reader (ALPR) data with out-of-state law enforcement agencies. ALPR systems, like the one that Los Altos is installing from Flock Safety, take pictures of every car going by, digitize their license plate, and record their presence. Police say this helps identify stolen vehicles, which are often used in crimes -- in principle, this should reduce crime, although the evidence that it actually works is very thin. This is a problem if someone from an abortion-restricted state travels to California for reproductive health care. By law , (AB 1242) police in California cannot assist out-of-state law enforcement in prosecuting people for coming here for an abortion. And by law (SB 34) California police cannot share any ALPR data with out-of-state agencies, according to our AG.  And  yet 71 police agencies did just that, and dozens still do. Many ...

 Last year the Los Altos City Council approved the installation of automated license plate readers (ALPRs) from a company called Flock Safety. While the efficacy of ALPRs as a crime-fighting tool has proven very difficult to see (for example,  this  and this show little statistical evidence for improvement), a new problem has come to light: It seems that Flock tends to be pretty casual about the rules. Two articles came out recently that call Flock's carefulness into question.  First, a Forbes article  (more reporting here ) found that Flock frequently put up cameras without regard to permitting or traffic safety considerations. "[I]n its rush to install surveillance cameras in the absence of clear regulatory frameworks, Flock repeatedly broke the law in at least five states. In two, state agencies have banned Flock staff from installing new cameras," Forbes correspondents Thomas Brewster and Cyrus Farivar report. Apparently, in the Silicon Valley tradition of ...

It was really great to open the Town Crier and see some actual crime data plotted out for all to see. Critical reporting on crime data is vital for all of us to know what's going on, so we can make good choices. Unfortunately, Los Altos Hills city manager Peter Pirnejad came to some incorrect conclusions from the data. We took a look at some of these claims back in October. In particular, it still seems that he is claiming it is impossible to know if preventative measures have been effective, which is hogwash of course. Now Pirnejad is saying that crime is down this year, and that it's probably because of the increased funding they've put on policing.  Spoiler: it seems like LAH has increased funding by at least $100k with no discernable impact on burglary. The city manager's main point is summarized in the graph in the article, which I'll reproduce here: credit: Christina Casillas, Town Crier There are a couple of things going on here. First of all, the data is p...

One afternoon on a remote work day, you are sitting at home, looking out the window before getting back to work on that TPS report that's due Monday. Outside, you see someone walking slowly down the street -- someone you don't recognize. "Who is that guy? What's he doing here?" you think to yourself. And maybe, "He seems suspicious. I think I'm going to call the police." It's important that we all work together to keep our communities safe. But sometimes, our natural tendencies can end up making our communities hostile and unsafe for innocent people.  "Bias by proxy" is an effect that can happen if the police get called for "suspicious people," and those calls are biased by race. If a Black man walking down the street is perceived as suspicious, and someone calls the cops to check up on him, then innocent Black people are going to get stopped and questioned by the police. Even if the police aren't biased, there will be bia...

 In addition to collecting and analyzing data from all police stops in California, the RIPA Board and the Department of Justice make an annual series of recommendations and best practices for policing. These recommendations have input from lots of different stakeholders: police officers, leaders of NGOs, DoJ lawyers, civil rights lawyers, state analysts, academic analysts, pastors and community members. The membership is really impressive . So the recommendations they come up with have a lot going for them. They are rooted in empirical data. They have input from experts, from officers with real-world experience, and from historically marginalized communities. We really should take them seriously. The recommendations are also very specific, and because of that, the documents are pretty long. Here's a high-level summary of some of the things recommended in past years; click through the links to see the full set of recommendations. 2021 Law enforcement agencies should proactively take...

 It was the summer of George Floyd that really shook my confidence in the police. Like most white kids, I was raised on the image of the friendly policeman -- if you ever have trouble, find a policeman (they were always men back then) and he will help you. But as more and more stories emerged... as more and more departments were revealed to have covered up, condoned, and even rewarded the most grotesque racism... and as I really listened to people of color talking about their own experiences, my childhood image was shaken. I respect all of those lived experiences. They are real and true. At the same time, the thing that I can offer to help is data analysis. That's not a very splashy gift; sorry about that. But it's what I have, so it's what I bring. One thing about data analysis is that you really can't do it in a vacuum, without context. It's not a machine, where you pour numbers in at the top and get crisp and unambiguous answers out the bottom. You have to know t...