Dex,
I saw no response to your request, so I will venture mine.
There have been breeding pairs in DC in recent years, and individuals
are not unknown on the Mall. I see a Peregrine here about every other
year, usually during some time from October to March. I haven't
seen any being mobbed; generally they are just scaring the pigeons
to death!
Jim
Jim Felley
Smithsonian Institution
irmss668@sivm.si.edu