What Information Are Stun Guns Recording?

In a story about a stolen Stradivarius violin, there's this:

Information from a stun gun company, an anonymous tip and hours of surveillance paved the way for authorities to find a stolen 300-year-old Stradivarius violin in the attic of a Milwaukee home, police said Thursday. [...]
Taser International, the maker of the stun gun used in the attack, "provided invaluable information" that the FBI tracked down in Texas and ultimately led police to Universal Allah, a Milwaukee resident, Police Chief Edward Flynn said Thursday.

The criminals stunned a musician as he was leaving a show at church, and drove off with his multimillion-dollar violin. What information could the stun gun company give the police that would be invaluable? Is it as simple as knowing who purchased the weapon, which was dropped at the scene? Or something weirder?

As the Milwaukee Police and the FBI began to conduct the investigation they reached out to us at TASER in order to identify possible suspects in the case. This was accomplished thanks to our Anti-Felon Identification tags (AFID). The AFID program enforces accountability for each use of a TASER device. This system releases dozens of confetti-sized markers upon discharge of a CEW cartridge. Each AFID contains a serial number that tracks back to the original purchaser of the cartridge. The large number of AFIDs and their small size makes it impractical to clean up. Therefore, law enforcement can pick up one AFID and contact TASER International for a complete trace on the serial number. At the time of purchase, we verify the identity and background of the prospective buyer with the understanding that we will not release the information and it will be kept confidential unless a TASER device is used in the commission of a crime. This information proved invaluable during the investigation on the Stradivarius violin. "We worked very closely with TASER International who provided us invaluable information that the FBI was able to track down for us in Texas," said Chief Flynn, "That information led us to an individual who had purchased this device."