On a reporting trip to Arizona to learn about the business of Tasers, Matt Stroud volunteered to have the technology tested on himself. “I didn’t know what to expect, and the short description is that it feels like being electrocuted over your entire body,” Stroud says. “You’re completely unable to move.” Stroud had two people on either side of him, and if it weren’t for them, he would have fallen to the ground.

“That gave me a real appreciation for how one company’s product could be unleashed on society through police departments, and it got me thinking about what other products were available,” he says. The result of his investigations is Thin Blue Lie: The Failure of High-Tech Policing (Metropolitan Books), a book about the promises and hype behind Tasers, body cameras, and more.

The Verge spoke to Stroud about how Tasers became so ubiquitous, why body cameras weren’t so revolutionary after all, and the policing technologies that are next.

This interview has been lightly edited for clarity.

Tasers play a big role in Thin Blue Lie. Can you tell me a little bit about the history of the Taser and how they came to be so widely used?

We can all empathize with the fact that when you have major police interactions that become international news stories — like Ferguson or Eric Garner — it touches people who are completely removed from such circumstances. Jack Cover was in exactly that kind of circumstance when the Watts riots of 1965 occurred over police brutality. He had nothing to do with Watts, but just like everybody else at the time, he heard about it, and he got to thinking what sorts of innovations might help police better do their jobs.

A couple of years later, in 1967, there was a major report that came out of the Johnson administration that addressed many police issues, and a specific section of the report talked about non-lethal weapons. The writers concluded that it’d be great if there was some kind of non-lethal weapon that police could have access to. It seemed like Jack wanted to solve that problem, so he started tinkering in his garage. His solution was basically to put an electric fence into a gun and fire it. He came up with a prototype that was shaped like a flashlight, and you could basically electrocute somebody. He worked for the better part of 10 years on this.

But it wasn’t successful at first, right? So how did it become so ubiquitous?

In January 1979, there was another one of those major police interactions that became a big story, which was the death of an African American woman in her 30s named Eula Love in Los Angeles. A bill collector came to her front door, and within a very short period of time, bullets were fired, and Eula Love was killed. It became a major story, and the city of Los Angeles still had the legacy of Watts hanging over the city, and city administrators realized that something needed to be done.

“I question whether the technology has served the ultimate purpose it was initially designed to serve.”

They wanted to know: were there any kind of non-lethal solutions the officers might have used in the interaction with Love? People within the LAPD were assigned to do some research, and one of the first weapons they came across was the Taser. That was one of the first times Jack Cover landed a big deal, though Tasers didn’t become something used by basically all police departments until probably the early 2000s.

What is the attitude toward Tasers now in police departments?

I think police love Tasers. They see them as another weapon they can use on their duty belt. Most of the police officers I’ve spoken with see it as something that can be used for compliance. What I think remains a concern with people who study Tasers and have spoken out against them is that the training is still pretty vague.

For years, the company pushed back against the idea that Tasers could kill and that they are lethal, even though by the early 2000s, there were dozens of people who had been killed in circumstances that were closely connected to being shocked with a Taser. There’s very little to ensure that the police officers who are instructing other police officers are explicit about the lethality, though the number of deaths is now over 1,000. A lot of the concerns have been downplayed, and I think that officers generally tend to like the option of a Taser but don’t think about the fact that the weapon really can kill.

Moving away from Tasers, another high-tech policing tool you write about is the CompStat system, which was pioneered in New York City and given a lot of credit for lowering crime rates. How did CompStat work, and was it hyped?

CompStat was a comprehensive program that was rolled out by two police leaders in the NYPD, Jack Maple and Bill Bratton. CompStat is basically an abbreviation for “computer statistics,” the very simple idea that police would gather current crime data and then map it using a computer so that they had a better idea of where crimes were happening so they could more effectively deploy police on the street.

Part of what made CompStat so successful — and Bill Bratton himself told me this — is that it’s comprehensive. The statistics were part of it, but the entire rollout was just as important, if not more important, than the stats. He emphasized that the stats were just one part of the program, and another part was bringing commanders together to talk about their specific precincts and how they were using data to counteract crime and what other factors they had to consider when thinking about how to reduce crime in the area. So my skepticism is more about how CompStat evolved after it was deployed with the NYPD. It seems to have some value there, but as more police departments saw its effects and wanted access to it, they started to market CompStat as not a comprehensive tool but just the technology itself. And I question whether just the technology itself could possibly have the same effect.

One of the most interesting parts of your book was the section about body cameras and how there was a lot of excitement there, but they ran into issues with access laws. What happened?

There were many conversations happening both in policing and in the public about the utility of body cameras and how they could be used. They could show what happened in interactions like the one with Eula Love and Michael Brown. There seemed to be a consensus that if body cameras were going to be deployed, police departments and prosecutors and communities would all have to have access to footage that was produced.

But as more and more body cameras started to be rolled out on the streets of various cities across the country, prosecutors and police departments and legislators started to realize that they didn’t want every piece of body camera footage released. Over the years, as body cameras have become more popular, there have been many laws passed restricting access to body camera footage. Police departments and prosecutors have fought really hard in some very significant cases to ensure that body camera footage is not released, so I question whether the technology has served the ultimate purpose it was initially designed to serve. I was a believer of body cameras at the very beginning. I still believe the concept is a good idea, but when you take away transparency, that turns them into a policing tool and not much else.

Is there an emerging policing technology that we should all be aware of? Or that maybe you researched but didn’t have time to include?

One of the technologies I am constantly fascinated by, but did not have time to get as deeply into as I wanted, is facial recognition technology. It has not developed as quickly as one might have expected, but as it gets rolled out to more and more federal agencies and police departments, it’s going to play a huge role. It’s going to give police the ability to make arrests on a much broader scale.

Correction April 2, 2019: The number of people killed by Tasers is now over 1,000. An earlier version of this article incorrectly said the number was over 10,000.