He’s either a gun-toting menace, or a well-intentioned boyfriend who simply forgot his car was loaded for bear.

During opening statements yesterday at the Manhattan trial of a Florida landscaper busted for having a handgun in his car during a routine traffic stop, neither side disagreed over the facts behind Jonathan Ryan’s arrest on the Upper East Side on Feb. 22, 2010.

Ryan drove to the Big Apple to see his “Late Show”-page girlfriend when he was stopped by cops for making an illegal right turn on red. The problem was, he had a legally purchased handgun stashed in his glove compartment, and he only has a license to carry it in Florida.

What both sides can’t agree on now is whether Ryan should serve a mandatory 3½ years behind bars if convicted of second-degree criminal possession of a weapon.

“He didn’t have a license to possess [the weapon] in New York City,” Manhattan Assistant DA Erin Tierney said flatly to jurors.

“I’m going to ask you to follow the law — nothing more, nothing less. At the end of the day, I’m going to ask you to render a verdict free from sympathy, free from prejudice.”

But Ryan has insisted that he simply put the gun in his glove box years ago and forgot about it.

His lawyer, Mark Bederow, told jurors that they have to find that Ryan, 29, “knowingly” had the Skyy CPX-1 pistol to convict for the felony.

“This is not about having a gun, it’s about knowingly possessing a gun,” Bederow said. “This man’s not a gun enthusiast, he’s not a gun collector, he’s not a member of the NRA.”

Ryan had been driving all day and night from his Lake City, Fla., to meet gal pal Ashley Shewey, 25.

Shewey, then a page for “The Late Show with David Letterman,” was moving back to Florida, and Ryan was going to help her pack.

Ryan turned from East 65th Street, and headed south on Park Avenue when he was pulled over by cops.

He reached for his car’s registration in his glove box, and that’s when the officers saw his 9mm pistol and its detached clip with seven rounds.

The defense failed to get the case tossed in December. Still, a judge handling pretrial motions said at the time that Ryan doesn’t deserve prison.