An active-duty military officer was stabbed in the Gaslamp Quarter late Thursday after pointing out errors to a man's military uniform.
It happened near Fifth Avenue and Market Street about 11:30 p.m.
Witnesses said the victim and a friend, who is a veteran, were pointing to a suspect, who was wearing a U.S. Army uniform.
Familiar with the uniform themselves, they asked him to adjust his Private First Class badge because it was facing the wrong way.
The man got defensive and from there they all took it to the sidewalk.
The three of them got into a confrontation and the suspect took out a knife, according to witnesses.
"The guy who they were saying wearing the stolen valor uniform pulls out a knife starts swinging, they're fighting, stabs one guy cuts him all up," witness Casey Phelans said.
Several people nearby jumped in to help.
The victim was stabbed in the arm and is being treated at a local hospital.
San Diego Police officers arrested 42-year-old Marco Dominguez to face charges in the stabbing.
Due to the Veterans Day holiday, NBC 7 has been unable to get confirmation from local military authorities on whether Dominguez is an Army veteran.
Veterans said it's noticeable when something is not right with a uniform.
One veteran says if he found himself in that situation, he definitely wouldn't have responded so defensively.
"I've got go to inspection tomorrow I better fix that you know? That's why I would have a lot of trouble believing this person was actually in the military. If he was in the Army he knew the specifics of the uniform there's no question about that," Vietnam veteran Paul Fusco said.
One of the men who confronted Dominguez last night says there was more than just one problem with his uniform.
He says he also forgot his mountain patches over his double swords.