Son Petitioning for Father - Police Background Check

[ANROMFER]

I-130 has been approved and cased moved to NVC.
Attorney is asking for documentation. I have all of it, except for a Police Clearance Record from the 25 years I lived in the US (out of status).

I read that the US embassy here in Chile does not provide fingerprinting services. How can I go about getting a Police Record from the US.
The FBI site wasn't very helpful either.