Nancy Guthrie missing case: Could AI come to the rescue? Gait recognition may provide key clues from FBI video

Videos of the night of Nancy Guthrie's disappearance, released by the FBI on Tuesday, could hold precious clues about the 84-year-old's suspected captors.

Analysis of the video by experts have already revealed several things, with some questioning the masked individual's firearms experience, and others pointing out that the calmness he exuded is likely indicative of a planned kidnapping carried out by someone with experience.

While efforts to trace the individual using facial recognition technology could face some hurdles, given that the infiltrator was wearing a mask, another technology could play a much more decisive role -- gait recognition.

"Along with facial recognition technology, there's gait recognition technology, which is just as accurate. Because the way we walk and the way we move is as much a fingerprint for us as our fingerprints," AI expert Kristian Hammond told CNN, commenting on how the technology could be leveraged to identify the masked individual in the video.

So far, investigators have revealed footage captured by Nancy Guthrie's door cam, but more footage, from neighbours and public surveillance, could also be leveraged to identify the individual in other clippings.

The already released footage by the FBI, though brief, shows the masked individual approach the door, turn, pick up vegetation from the yard, and move back into porch to try and cover up the door cam.

Although his face was not visible, clues gleaned from his movement are likely to be invaluable.

"What's going to be interesting here is figuring out a way to take all of these features [the suspect's movement] and use them as a way to guide the mining of other videos," Hammond told the news outlet, explaining how AI could be used.

Hammond explained that it was likely that several other cameras in the area could have picked up the suspect during his movements.

"There will be people in the neighbourhood who also have cameras and those cameras may have a different subscription service and there maybe more data on those cameras," Hammond said.

"...Getting to that might actually get to more information about the movement," the AI expert added, explaining how these bits and pieces could help authorities construct a better movement profile of the suspect.

Initially, following Nancy Guthrie's disappearance, authorities had hit a roadblock due to footage from the night being unavailable.

That, however, was remedied after Google engineers, over a period of 10 days, painstakingly recovered the data from traces of data in the search giant's servers, despite Guthrie not having a cloud backup of the camera footage.

Hours after the video's release by the FBI, authorities detained a person for questioning and searched a property in Rio Rico, marking the first significant leads in the case that has left authorities as well as the American public baffled.