I'm at a loss to understand how this could have possibly happened. An off-duty Dallas police officer mistakenly walked into an apartment she thought was her own and shot a man dead Thursday night, police said. Police and the district attorney want to get to the bottom of what happened. "Preliminary information suggests that the officer arrived home in full uniform after working a full shift," according to a statement Friday on the Dallas police blog. "The officer reported to the responding officers that she entered the victim's apartment believing that it was her own. At some point, the officer fired her weapon striking the victim. "Responding officers administered aid to the victim, a 26-year-old male, at the scene. The victim was then transported to the hospital and pronounced deceased. Next of kin notification has not been made at this time." Police have not identified the officer, who will be "placed on administrative leave pending the outcome" of the investigation. Journalists who spoke with police "said the officer who fired her weapon had not been interviewed. Officials would not answer questions as to how the mix-up happened, or how the officer got inside someone else's apartment." The Southside Flats, where the shooting occurred, are a block away from Dallas police headquarters.