Good point. I don't think I've ever seen a trooper step out of their patrol car without putting on a hat. However it's not required for giving a citation.
www.wusa9.com
To verify whether a ticket is valid if a trooper is not wearing his or her hat, we asked Corrine Geller of Virginia State Police and Rob Snyder of Maryland State Police.
“The hat has no bearing on the validity of the ticket. It’s our department’s policy that a trooper must be wearing a hat when out of the building or making an arrest," Geller said. "But there’s nothing in state code that he must be wearing his hat when issuing a citation.”
"Absolutely a ticket is valid as long as a trooper is acting within the parameters of his job, that is absolutely a valid ticket," Snyder said. "Never heard that question before--I can imagine there’s been urban legends passed around from time to time."