Don't just report them to the police, file an ic3 at ic3.gov if they've asked for money for these fake reasons. Don't let it escalate that far if you can help it, just report them as a scammer if you're really familiar with their strategies after reading this article.
If this person really sounds threatening to your safety, consider the non emergency police phone number to your local police station. The emergency lines need to be kept clean of any distractions like these unless this person is threatening you in your home.
I've had a dating scammer pretend to be a sheriff but I knew his phone number was not authentic. He threatened me in my home so that's the point at which it escalated to a 911 phone call for me.
Any other circumstances I'd call the non emergency number if it's just an Internet criminal.