Nine-second surveillance footage in Brooklyn saw a woman execute her ex-girlfriend in a rapid, brazen assault in broad daylight on Wednesday, April 21.

The assassin, Latisha Bell, 38, surrendered to police hours later at the 78th Precinct station house. She has been charged with second-degree murder and criminal possession of a weapon.

The victim, Nichelle Thomas, a 52-year-old mother of two, was shot just before 1 p.m. in Park Slope at Fourth Avenue and St. Marks Place.

According to footage obtained by The New York Post, as Thomas went to open the door of a deli, Bell sprinted up to the corner of St. Marks Place and pulled a gun, and shot Thomas.

The victim crumpled to the ground. According to police, Thomas was rushed to Presbyterian Brooklyn Methodist Hospital, where she died at 1:26 p.m.

Bell was accused of shooting Thomas point-blank in the back of the head and fleeing.

Throughout the video conference of her proceeding, Bell appeared calm, respectfully addressing the judge and telling other defendants pending their trials to be silent so she could hear the proceeding. After refusing to seek a bail request, Bell’s defense counsel, Michael Sheinberg, requested a psychiatric evaluation for Bell.

Police did not immediately reveal the reason for the shooting.

Prosecutors said Thursday that the murderer admitted to ending their tumultuous two-decade relationship by gunning down her ex-lover in broad daylight on a Brooklyn street.

According to the victim’s friend, the pair broke up about three years ago. In court, Brooklyn Assistant District Attorney Wilfredo Cotto disclosed 13 domestic incident reports over their long relationship, with Bell being known as the aggressor ​in 10 of them.

The suspect’s sister said her jailed sibling was mentally ill and blamed the victim for trying to rekindle their relationship.

“When my sister left her she should have kept going,” the sister, who declined to give her name, told reporters outside Brooklyn Criminal Court. “You don’t play with the mentally ill.”

In such a normally safe neighborhood, daylight violence shocked witnesses.

”It’s scary. If the bullet hadn’t hit her, I might have been the one hit,” said deli worker Mohammed Ali, adding that there had been lots of people there inside the place.

He said he heard one shot, which he knew was from a gun.

“The man next to the ATM machine said the lady went down,” Ali said. “At that point, I said there’s got to be something wrong, so I looked at the cameras.

He said he ran outside and saw “a lady lying face-up on the sidewalk and above her eyes was a hole with blood coming out.”

“I’ve been working here for 12 years and I’ve never seen anything like this,” said Ali.

As Andrea Iglesias looked at the scene of the latest act of bloodshed, he said. “It’s unreal what’s happening in this city.”

“This is a good area. People don’t get shot here, especially in broad daylight on a busy intersection. There’s so little enforcement anymore, people feel emboldened,” added Andrea.

According to NYPD reports, this is the first shooting in the area this year, and it comes amid a nearly year-long spike in Big Apple gun violence.

As cities historically see an uptick in gun violence over the summer, the mayor’s office unveiled a proposal on Tuesday to curb this problem during this period—but the plan just echoed last year’s failed policing strategy.