Flanked by more than 40 police officers and prosecutors, Gov. John Lynch vetoed legislation today that would have made it easier for people to use deadly force in public places.

“It’s a nightmare scenario,” said Strafford County Attorney Janice Rundles, one of many in the law enforcement community opposed to the bill.

The bill would have allowed people to use deadly force in any place they had a right to be if they thought someone was about to commit a crime against them. Now, people must retreat when it’s safe to do so unless deadly force is required to prevent kidnapping, rape or murder.

Supporters argued that someone confronted by the threat of violence shouldn’t have to decide whether it’s safe to retreat or not. They also argued that people who act in self defense shouldn’t have to fear prosecution.

But Lynch and many police officers had visions of shootouts on the streets.

“SB318 would authorize any shopper to instantly shoot and kill a thief who had grabbed or tugged at the shopper’s purse or briefcase, regardless of how many shoppers might be placed in harm’s way by such actions,” Lynch said in his veto message.

Rundles said the bill would have made it harder to prosecute a case of road rage where angry drivers intentionally smashed into each other’s cars on a busy highway.

Attorney General Kelly Ayotte said drug dealers would have gained a new right of self-defense if they shot another criminal who tried to rob them and killed a bystander in the process.

The Senate narrowly passed the legislation 12-11, with Manchester Sen. Andre Martel saying afterward he’d voted in favor by mistake. The House voted it down at first but passed it on the second shot, 193-134.

Lynch said he seen no evidence that anyone had been unfairly prosecuted in New Hampshire for acting in self defense.