Video that appeared to show the moment Kate Steinle was shot by a homeless illegal immigrant triggered gasps in court Wednesday, as a police officer explained what he found at the scene.

San Francisco Police Department Officer Craig Dong was the final witness of the day in the trial of Jose Ines Garcia Zarate, who's charged with killing Steinle on July 1, 2015 on Pier 14 in San Francisco. Dong is an investigator with a background in video forensics.

During his testimony, video provided to him that was recorded from a distance was played for the jury. It showed Steinle falling, the suspect walking away and something splashing in the water.

When the part of the video showing Steinle was played, people in the gallery of the court room could be heard gasping. The video was played back again, during which an alternate juror stood to get a second look.

In addition to the video, Dong talked about how he'd received photos from witnesses on the scene and distributed them to officers looking for the suspect.

During Dong's cross examination, he admitted that investigators hadn't looked at video from before the shooting. The defense team stressed the importance of this, arguing that earlier video could have shown that the weapon was already on the pier, backing up Zarate's claim that he found the gun there.

The day began with resumed questioning of SFPD Officer Raymond Ortiz, who was part of the CSI unit that responded to Pier 14 the night Steinle was killed.

During his testimony on Tuesday, Ortiz showed jurors video and several pictures showing the entire length of the pier, including the swivel chair the defendant Zarate was in, the exact spot where Kate was hit, and the location of several witnesses in relation to them.

SFPD Officer Andrew Bryant, who arrested Zarate after the shooting, took the stand next. Bryant told the jury that he noticed the suspect on the scene and when Zarate saw him, his eyes got very big, "like deer in headlights," and quickly walked the other direction.

Bryant said he pulled out his weapon and yelled "stop," but the suspect kept walking. A plainclothed officer appeared and ordered Zarate to the ground, which he obeyed.

He said Zarate was cuffed and searched before being sat in the back of the police car. About 45 minutes later, the suspect's hands were put in bags to protect any gun residue that was potentially on them.

When the defense team cross-examined Bryant, they suggested that perhaps the residue ultimately found on Zarate's hands was actually transferred to him from an officer.

The jury also heard from SFPD Bomb Squad Officer Scott Hurley, who's part of the "underwater hazards device team" and recovered the murder weapon from the ocean floor.

The defense team questioned him regarding tides and currents between when the gun was dropped in the water and when it was located a day later.

None of the victim's family members were seen in court.

On Tuesday, jurors heard from Michelle Lo, a witness to the slaying.

KATE STEINLE TRIAL FEATURES TESTIMONY OF WITNESS TO KILLING BY ILLEGAL IMMIGRANT

Lo said she was on vacation in San Francisco with her family at the time. She remembered a man dressed in black who "looked like a homeless person" and was spinning around in a chair "grinning and laughing" who made her uncomfortable.

She said she and her family continued along a pier before hearing a "very sharp scream" and seeing a woman on the ground. And she said she saw the same man from earlier walking away.

Zarate, 54, admitted shooting Steinle, but says it was an accident.

Steinle's father testified Monday that before she died, she said to him: "Help me, Dad."

The prosecution said those were her last words.

KATE STEINLE CASE THAT LED TO DEBATE OVER US SANCTUARY CITIES, TRUMP’S CALL FOR WALL IS UNDER WAY IN COURT

While Garcia's immigration status is what brought the case into the national spotlight, jurors will not hear evidence about that, and it will not be a factor in the trial.

Steinle's slaying became a signature issue for Donald Trump as he was running for president. He invoked the slaying in calling for the construction of a wall on the Mexican border and stepping up deportations and cracking down on illegal immigration.

Fox News' Jennifer Girdon in San Francisco contributed to this report.