How Long After Being Caught By Speed Camera Do Dvla Notify You?

While driving recently I *think* I got caught speeding, but I’m not sure. I have been waiting to see if I get letter in the post but so far nothing.
I was wondering though, if I had been caught, how long does it take the DVLA to send out the letter anyway? Its only cos it was on Good Friday I think I got caught and I was wondering the delay was simply because of the Easter bank holidays.
Anyone have any idea how long it may be?

Can A Police Officer Issue A Speeding Ticket Without Pulling You Over?

I was driving home late at night through a residential area when I passed what looked like two cops and a pedestrian. I’m pretty sure I wasn’t speeding (25mph), but one of the cops flashed a white light at me as I passed. Then he walked into the middle of the street and I saw a red light flash behind me. I want to know what the heck happened and if this means I’m going to receive a ticket in the mail. Thanks.