All of my unwanted calls from 951-381 have been from the Fraternal Order of Police seeking donations. No message was left and the caller id was california.
As a retired cop, I recommend never participating with these type of "Law Enforcement" solicitations. They are typically boilerroom operations with no affiliation with Law Enforcement other than being contracted by a labor association to which they guarantee a particular dollar amount. The solicitor then keeps everything above the guaranteed amount. As with most boilerroom operations they will use any underhanded way to try and separate you from your money.