Although not mentioned clearly in the complaint it's very possible the initial matching was done through the FBI's or another automated query system. This is a

Although not mentioned clearly in the complaint it's very possible the initial matching was done through the FBI's or another automated query system. This is a standard practice used in law enforcement investigations - capture fingerprints however you can and submit them to the FBI, which returns a report of possible matches. The automated matches would need to be followed up on with manual comparison, esp. due to the unusual nature of the fingerprint capture here, and this manual comparison is going to be the part mentioned in the complaint because it most clearly establishes a link.