It's telemarketers trying to raise money for The Fraternal Order of Police.
I'm not sure who they have hired for this round of calls but you can Google for information about them and see that there have been some complaints about the telemarketing firm they have used in the past.
 Dec 08th, 2009
Call from this number around 2:20 PM on a Wed, Caller ID'd as TX FOP, did not answer, rang four times, machine picked up, no msg left!
Mr. Mom
 Oct 28th, 2009