Bitcoin and other cryptocurrencies undoubtedly offer new opportunities for financial transactions. However, they can also be used for purposes of financial crime, such as fraud and money laundering. The absence of central control and the pseudonymous nature of transactions make cryptocurrencies appealing for illicit activities.
What do you think can be done to mitigate the risk of cryptocurrencies being used for criminal purposes? What measures should be taken?

It's not Bitcoin's or crypto's fault, fiat is also being used by criminals and on a much larger scale than crypto. There's nothing you can do to prevent it really. I don't think KYC or similar attempts to deanonymize users are necessary as it will likely make many legitimate users stop using it.