New York police Sgt. Richard Blake had made it clear: The man he had shot in the face on a Brooklyn street while off-duty was a threat, he later told police.

But a surveillance camera perched over a sidewalk that captured the incident has complicated the picture of what exactly led Blake to shoot Thavone Santana early Thursday and suggested an effort to plant a weapon to frame him.

The video, without audio and published first by NBC New York, shows 21-year-old Santana approaching Blake from behind. A conversation ensues and appears to grow more tense. Blake, 40, backs up, pulls out a handgun and positions himself in a shooting stance.

BREAKING VIDEO, off duty NYPD sergeant shoots unarmed man In Brooklyn, following a dispute over a woman. pic.twitter.com/TNTrFbD2ZD

— New York City Alerts (@NYCityAlerts) August 3, 2018

NBC's video freezes as Santana braces for a shot, leaving out the two shots that Blake fires at Santana, striking him once in the chin.

Blake paces back and forth, then appears to pat down Santana's pockets. He then appears to take a sheathed knife from his own back pocket, the New York Times reported, slides it from its sheath and drops it next to Santana's crumpled body. He then pauses for a moment and retrieves the knife, the video shows.

The New York Police Department said Thursday that Santana was in stable condition.

"The video captures actions that raise serious questions and require further investigation," Detective Sophia Mason, a department spokeswoman, told the Washington Post in a statement. Blake was placed on administrative duty, the department said. The Timesreported that he was stripped of his badge and service weapon.

The Brooklyn District Attorney's Office, which is investigating the incident, was at the scene shortly after the shooting, a spokesman told The Post.

Authorities told reporters Thursday that Santana pretended to have a gun and that he tried to rob Blake, the Times reported. But on Friday, police officials told the paper that Blake said there was a threat with a gun but did not mention attempted robbery.

It is not clear where the discrepancy arose, and the department did not respond to requests for comment about it.

On Friday, Police Commissioner James O'Neil said in a news conference that no firearm had been recovered. The video does not appear to show Santana reaching for or pretending to reach for a weapon.

One aspect the police have yet to address: the motive, and whether the trouble might have been over a woman.

O'Neil and Department Chief Terrance Monahan shied away from questions regarding any history between the men, saying only that police believe the incident began over a prior dispute.

But a neighbour of Blake's girlfriend told the Times that several people tried to break down the girlfriend's door hours before the shooting for unclear reasons. Chris Banks, a community activist, told the paper that the men were fighting over the woman. He could not be reached by the Post.

Blake left his girlfriend's apartment around 5am to go to his Queens precinct to start his 7am tour. The confrontation happened on the way, the paper said. The report did not name the woman.

Attempts to contact Santana's mother, who was briefly quoted in the Times report, were unsuccessful. Blake also could not be reached for comment.

State Assemblyman Charles Barron, a Democrat who represents Brooklyn, told the Timesthat Santana was sedated and handcuffed at the hospital. It is not clear whether he will be charged with a crime.

Blake was previously involved in a violent incident involving a woman. He was suspended for 36 days and placed on dismissal probation in September 2017 after he was charged in connection with punching his girlfriend in the face, the New York Daily News reported.

The suspension occurred nearly 11 months after he was arrested. His status, dismissal probation, allows the force to fire him for any reason within a year-long period, the paper reported. That window will close at the end of next month.