and david servin, a talented musician who planned to go to business school. >> when we found out whatappened, it was unbelievable. >> reporter: did it make it hurt worse once you learned that it was a police officer who hit them? >> i was disgusted that it was a police officer. you see them racing around all the time. and, you know, this time they didn't get away with it. >> reporter: so, why do cops speed? >> because they can. >> reporter: justin hopson is a former new jersey state trooper who wrote a book on corruption in his agency called "breaking the blue wall." and when they're speeding, where are they going, home? >> lunch, meeting another police officer. it's the mentality of "hey, i have a badge and the ability to go as fast as i need to go." >> what's he doing? what's he doing? >> reporter: the problem's gotten so out of hand, some motorists are striking back, catching speeding cops in the act. here, a caravan of hot rods on a joyride down a new jersey highway hit speeds over 100 miles per hour. >> doing 100. >> a new jersey state trooper suddenly appears, he's going to put