RICHMOND — A man allegedly caught breaking into a Post Road couple’s apartment early Wednesday morning was shot by a resident after the suspect tried to break through the front door a second time.

Richmond police Chief Scott MacMaster said the suspect, Shad Hembree, 42, was wounded but that it did not appear to be serious. He was struck by a single shot from a handgun fired by Trevor Whitney, 28, who lives with his girlfriend, Lindsey Levasseur, 23, at the residence.

Whitney said Wednesday afternoon he didn’t want to shoot the man, but when it became clear he was trying to force his way in, he felt he had to take action to protect himself and his girlfriend. Whitney, a Marine from 2007 to 2013 who served tours of duty in Iraq and Afghanistan, aimed at Hembree’s shoulder because he didn’t want to kill him.

“I thought, ‘I’m not letting this guy in,’ ” Whitney said of the early-morning incident. “I didn’t want to shoot him.”

Levasseur said she’s grateful her boyfriend hadn’t yet left for work, which would have left her alone in the apartment. She praised Whitney’s shooting skill and his choice not to kill the suspect.

“I’m so happy he shot him where he meant to shoot him,” she said. “I think he handled it beautifully. I know if he wanted to kill him, he would have.”

MacMaster said police were called around 5:45 a.m. Wednesday and the woman caller said a man was in her apartment and her boyfriend was yelling at him to get out.

Whitney said he was getting ready to go to his job at the Loomis armored truck company around 5:30 a.m. and was about to make coffee when a man he had never seen before came in their unlocked front door. The man was barefoot and wearing tattered camouflage pants.

Whitney asked the man who he was and what he was doing there, and the man, later identified as Hembree, responded by asking the same questions back. The man was holding a large metal flashlight “like he had hostile intent,” Whitney said, and refused to leave.

Whitney said he picked up his Sig Sauer .40-caliber semi-automatic, which he uses for work, from the kitchen table and warned, “I will shoot you. You need to leave.”

The man backed out of the apartment and started down the exterior stairs from the couple’s apartment.

Whitney said he went back inside, locked the door and told Levasseur to call 911. Whitney said Hembree came back up the stairs and started shining his flashlight through the glass of one of the front doors. He then used the flashlight to break the glass out of the door.

That’s when Whitney fired the pistol.

MacMaster said Hembree then ran down the exterior stairs from the apartment and into the driveway and, despite the gunshot wound, started smashing the windows of the Whitney’s vehicle.

Whitney said he called his mother, who lives next door, and told her to make sure her doors were locked.

Hembree went up to her home and started looking in windows, Whitney said, before he coming back up the apartment stairs to stand on the porch staring at Whitney.

Whitney said that when he warned Hembree he would shoot if he came into the apartment again, the suspect sat in a lawn chair on the porch until a deputy from the Sagadahoc County Sheriff’s Office arrived.

Hembree was taken by ambulance to MaineGeneral Medical Center in Augusta. MacMaster said an officer would stay with Hembree in the hospital, and when he is released, would be taken to Two Bridges Regional Jail in Wiscasset.

Hembree was charged with burglary, but MacMaster said additional charges are likely.

Whitney was not charged with any crime.

“It was clearly a situation of self-defense,” MacMaster said.

MacMaster said the victim and the suspect are neighbors but did not know each other and never had contact with each other, and their homes on Post Road are separated by woods.

Levasseur said they’re worried that Hembree could be released on bail and return to their home, and there could be a repeat of the incident. Whitney said they’ll keep their front door locked from now on.

MacMaster said police think Hembree’s actions in the case might be related to mental illness. He said police had been called to his home in the past to check on him, though none of those calls involved criminal activity.

“I don’t think even he knew what he was doing,” Whitney said.