I would have thought that if one person speeds and the cop has a radar reading for that particular road user, it is for him and him only. You should be able to get out of your fines (you and both friends) if you contest it together. If all 3 of you were to get booked also I would think he needs to prove it with individual radar readings. Compare time of day with your friends fines. Dad got out of a radar detected fine a few years ago because the second cop at the scene cleared the radar and started trying to catch next person, then he asked if he could see the reading as he didn't believe he was speeding. Long story short, he went to court and got out of it because the cop at the scene couldn't prove he had been speeding as the reading had been cleared. If you have a good driving record as well as being polite and presenting well at court that should help your cause also...