We’ve all seen the security camera photos of the Boston Bombing suspects that were released by the FBI last week. But at the time, many wondered why they were released to the public at all. The FBI has access to the most high-level, cutting edge technology available, after all. And if federal agencies had images of the suspects in their possession, couldn’t they just use run those images through facial recognition software to identify a match?

If you’re a regular watcher of TV shows like NCIS, Law and Order, or Las Vegas, which frequently use facial recognition software with near 100% accuracy, you may be surprised to find out that real-life results are not quite as easy to attain. Facial recognition works best, if at all, using very high-resolution photos. It becomes virtually useless with grainly, low-res images captured through video surveillance or cell phone cameras.

Boston Police Commissioner Edward Davis was later quoted as saying, “The technology came up empty even though both Tsarnaevs’ images exist in official databases: Dzhokhar had a Massachusetts driver’s license; the brothers had legally immigrated; and Tamerlan had been the subject of some FBI investigation.”

Still, video surveillance itself was extremely valuable in tracking down the suspects. According to The Washington Post:

The work was painstaking and mind-numbing: One agent watched the same segment of video 400 times. The goal was to construct a timeline of images, following possible suspects as they moved along the sidewalks, building a narrative out of a random jumble of pictures from thousands of different phones and cameras. It took a couple of days, but analysts began to focus on two men in baseball caps who had brought heavy black bags into the crowd near the marathon’s finish line but left without those bags.

Of course, another reason the images were released to the public was to limit misinformation being circulated by Reddit and other social sites. The Post adds:

In addition to being almost universally wrong, the theories developed via social media complicated the official investigation, according to law enforcement officials. Those officials said Saturday that the decision on Thursday to release photos of the two men in baseball caps was meant in part to limit the damage being done to people who were wrongly being targeted as suspects in the news media and on the Internet.

Even without facial recognition software, the Boston Police Department and FBI identified and apprehended their suspects in a matter of days with sheer work ethics and their inexhaustable dedication. And that’s far more impressive than anything you’ll see on TV.