The time was registered by the $600,000 "shot-spotter" system, which triangulates the location of gunshots and alerts the San Francisco Police Department.
However, officers following up on the scene found neither the body nor any suspects because of a broken streetlight, according to officials cited by the San Francisco Chronicle.
Instead, neighborhood residents stumbled across Johnson's body at dawn, hours after the crime.
Meanwhile, French officials investigating the death of French and American citizen Hugues de la Plaza, 36, in his Hayes Valley apartment in June of 2007 have determined that the case was a homicide, and not a suicide as the SFPD had been suggesting to the public.
If I were a betting man, I'd wager that Johnson's murder will be one of dozens of lingering open homicide cases in the SFPD's files.
San Francisco's "clearance rate," or cases considered closed by the department after a conviction or death of the primary suspect (and in San Francisco, it's usually the latter), is the worst of any major American city.
Which would explain the apparent willingness by detectives to reason that de la Plaza stabbed himself multiple times, starting at the door to his building and continuing up the stairs to his apartment, locking his door behind himself for good measure. A suicide, after all, has no suspect to apprehend or put on trial.
While the expensive shot-spotter system worked as intended, hopefully the Police Commission will look into why officers who come equipped with flashlights were foiled at the scene of Johnson's murder by a broken overhead bulb.
And why French investigators arriving months later came to a different, if seemingly obvious, conclusion than the one arrived at by local authorities in the de la Plaza case.
Since the SFPD's theory in the latter case presumes de la Plaza managed to dispose of the knife he was assumed to have stabbed himself with, maybe investigators are looking into whether Johnson shot himself and later disposed of that weapon in an obvious suicide.