Criminals were behind roughly 90 percent of all bitcoin transactions five years ago – a figure that has now declined to 10 percent.

That’s according to Lilita Infante, a special agent from the U.S. Drug Enforcement Administration who spoke to Bloomberg about changing trends in the relationship between the cryptocurrency and criminal activity.

“The volume has grown tremendously, the amount of transactions and the dollar value has grown tremendously over the years in criminal activity, but the ratio has decreased. The majority of transactions are used for price speculation,” Infante was quoted as saying.

Despite the shift from criminal use to investment and trading, though, the total volume of criminal bitcoin transactions has still increased over the years as dark market activity has grown. It’s just that the proportions have effectively swapped, according to Infante.

In fact, given this rapid growth in interest for the different use cases of cryptocurrency, U.S. law enforcement has since caught on to the technology to some degree using blockchain technology to trace cases of money laundering and illegal drug trafficking.

Even so, Infante maintained that U.S. law enforcement is ahead of the game, telling the publication that “we still have ways of tracking them” and noting that, at least for the time being, the majority of criminal dealings in cryptocurrencies still occur on the public bitcoin blockchain.

“The blockchain actually gives us a lot of tools to be able to identify people … I actually want [criminals] to keep using them,” she told Bloomberg.

Handcuffs image via Shutterstock