"Loudoun Deputies FOP" is probably the Loudoun County, VA Sheriff Fraternal Order of Police chapter. They might be soliciting ads for their 2016 calendar.
Most of these orders of police, sheriffs, etc are all scams or the majority of the money you donate goes to the telemarketing company. I had a John Riggs leave his number on my phone with no message.
From the FOP website:
The National Fraternal Order of Police does not conduct telephone solicitations. However, some State and local FOP lodges do. If you have a question about a telephone call you received requesting that you make a donation to the FOP, please contact the local FOP lodge in your area or the FOP State Lodge in your state.