Reading the link, it appears that they're not identifying criminals qua criminals—this isn't a
Minority Report method, which the blurb suggested.
It seems they're identifying individuals by their gait, so that they can extract that info from CCTV recordings of crimes, and looking for that person elsewhere. The gait info appears to be easier to extract from fuzzy videos than, say, faces.
Unfortunately, they throw around a “99% accuracy” statistic without giving enough info for it to be meaningful. Is that 1% false positive? false negative? For all they say, it could mean in a crowd of 1000, 10 will be flagged.
Of course, some bright person will now suggest we analyze all public camera recordings to find putative criminals. There's no problem if you've done nothing wrong....