Neighbor slain in ‘wrong’ apt.

Cop walked in, opened fire

A Dallas cop mistakenly walked into her neighbor’s apartment, pulled a firearm and gunned down the unsuspecting resident in his own home, authorities said Friday.

The police officer immediately called for help and first responders attempted to revive 26-year-old victim Botham Shem Jean following the incident that unfolded Thursday at about 10 p.m., officials said.

Jean was rushed to Baylor University Medical Center, where he was pronounced dead.

The Texas Rangers have been tasked with leading an independent investigation.

The Dallas cop, who is white, will face manslaughter charges, officials said. The victim was black.

“This is a very unique situation,” Police Chief U. Renee Hall told report- ers on Friday.

“We have ceased handling it under our normal officer-involved shooting protocol.”

The name of the officer, who was not injured, wasn’t immediately released. The five-year veteran has been placed on administrative leave.

Police didn’t reveal how the cop got into Jean’s home, or whether the victim’s door was left open or unlocked.

Neighbors at the South Side Flats complex said they can access their units with a key or through a keypad code.

“Right now, there are more questions than we have answers,” Hall said.

Jean was a devout Christian and a talented singer, family and friends said.

He worked in risk assurance for the accounting and consulting firm PricewaterhouseCoopers in Dallas.

“It just feels like a nightmare. I wish I could wake up,” the victim’s mother Allison Jean told NBC News.

“He impacted the lives of many. I’m getting calls from all over the world.”

His uncle Ignatius Jean said the slaying left relatives looking for answers.

“You want to think it's fiction . . . and you have to grapple with the reality,” he said.