HOUSTON — A Dallas police officer’s explanation that she killed a black neighbor who lived above her because she mistook his apartment for her own has been dismissed as implausible and self-serving by his family and their lawyers.

Experts on police training and psychologists, however, are split as to the credibility of Officer Amber Guyger’s story about how she came to kill 26-year-old Botham Jean, and that credibility will be key to whether a grand jury will indict Guyger and whether she could persuade a trial jury that the killing was tragic, but justifiable.

Botham Jean

Guyger, 30, has been booked on an initial charge of manslaughter in the Sept. 6 killing of Jean, whose funeral was Thursday, exactly a week after the deadly encounter. Guyger said that she parked on the wrong floor of her building after returning home from work late that night and she mistakenly entered Jean’s apartment, which was right above her third-floor unit.

She said it was dark inside and she thought Jean was a burglar, and that she shot him after he didn’t obey her “verbal commands.” She said she only realized she wasn’t in her own home after she had shot him and turned on the lights.

Lawyers for the Jean family have criticized the handling of the investigation, alleging that Guyger has been given preferential treatment.

“Botham Jean is not here to give his version of what happened because he’s dead,” said one family lawyer, Benjamin Crump.

Some experts who aren’t connected to the case say Guyger should have stopped short of using deadly force.

“Law enforcement has no place for fearful officers,” said Jameca Woody Falconer, a police psychologist based in St. Louis. “Fearful officers make hasty decisions and bad decisions. In this situation, the officer allowed her fear to influence her decision-making and it cost an innocent man his life.”