A Florida man was so startled when his son-in-law jumped out from behind some bushes for a birthday surprise that he shot and killed him, authorities said Thursday.

Richard Dennis, 61, won’t be charged in the accidental shooting of his daughter’s husband, Christopher Bergan, Santa Rosa Sheriff Bob Johnson told reporters at a news conference.

Bergan, 37, had flown in from Norway on Tuesday for the surprise and, around 11:30 p.m., knocked on the back door of his father-in-law’s Gulf Breeze home, then hid behind bushes.

When Dennis answered, Bergan sprang out while making a growling sound, cops said.

That’s when Dennis fired one round from his .380 semi-automatic firearm, hitting his son-in-law in the heart and instantly killing him, Johnson said.

“He was totally startled,” Johnson said of the older man.

Authorities said the incident was a sad case of mistaken identity.

Earlier that evening, Dennis had gotten into an argument with another relative because that person had come by the home and loudly banged on the front door.

When he heard the loud raps again an hour later, Dennis believed it was that same relative and opened the door while armed.

“I’m not going to second-guess Mr. Dennis for what he did. Here he is, he had just had a confrontation at the front of his house,” said the sheriff. “Couple hours later, someone is banging on his back door, and it’s a fenced yard.

“And then someone jumps out of the bushes,” Johnson said. “You can’t really say anything against Mr. Dennis for doing what he did.”

“I think it was just a horrible accident, that should never have happened.”