CHICAGO (CBS) — After four days of testimony, prosecutors rested their case Thursday against Chicago Police officer Jason Van Dyke.

His defense will begin presenting the first witnesses on Monday, seeking to convince jurors Van Dyke was justified when he shot and killed 17-year-old Laquan McDonald in 2014.

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A total of 24 witnesses testified for the prosecution over the course of four days. After they wrapped up their case Thursday afternoon, defense attorney Dan Herbert asked Judge Vincent Gaughan to deliver a direct verdict declaring Van Dyke not guilty, arguing there was no evidence the shooting was anything but justified. Dan Herbert arguing officers are allowed to use deadly force. And the fact Van Dyke fired 16 times is irrelevant. (EVEN 16 SHOTS)

“As everyone knows, this is not an excessive force case, this is a murder trial,” attorney Dan Herbert said.

A ballistics expert testifying for the state on Thursday showed video of what firing 16 shots in 14 seconds with the same type weapon looks and sounds like.

“He was taking the time to aim each shot, it was deliberate methodical – only way to describe that,” said ballistics expert Scott Patterson.

Looking at the dash cam video the night Laquan McDonald was shot, a “use of force expert” said there was no imminent threat.

“The threat posed by Mr. McDonald did not rise to the necessity of using deadly force,” Patrick Urey said on the witness stand.

The big question now is whether Van Dyke will take the stand next week in his own defense.

Earlier, former Navy officer and ex-FBI agent Urey Patrick, an expert on police use of force, testified he did not believe it was necessary for Van Dyke to use deadly force against McDonald. He told jurors Van Dyke kept shooting McDonald “long beyond the point of being reasonable.”

Patrick said McDonald was too far away from Van Dyke to harm him with his knife, as the officer had his gun drawn and pointed at the teenager immediately after leaving his squad car.

He also noted McDonald never threatened officers, or moved toward the officers who were following him, but instead was moving away from the police.

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“The risk posed by Mr. McDonald did not rise to the necessity of using deadly force to stop it,” he said. “He is a risk, there’s no question. He’s been noncompliant, and he is armed with a knife. But there is nobody within reach of him, and he is moving away from the only people on the scene who could be imminently in reach of him.”

Patrick also noted there were no innocent bystander near McDonald at the time, and that a fence was blocking his path away from officers. He said other officers at the scene “acted reasonably and properly” by following and trying to corner McDonald, but not opening fire on him, although he agreed with defense attorneys that the fact other officers didn’t shoot McDonald was not relevant in determining if Van Dyke was justified in doing so.

Prosecutors also called a ballistics expert to the stand on Thursday to walk jurors through a slow-motion, enhanced video of the shooting. FBI ballistics expert Scott Patterson told jurors that what appear to be “puffs of smoke” on the video were actually “plumes” of dirt or debris from bullets hitting the pavement as McDonald was shot while he was on the ground.

The prosecution’s final witness was Jose Torres, a bystander who was driving his son to the hospital when he saw police following McDonald down Pulaski Road. Torres told the jury he had a clear view of Van Dyke shooting McDonald, and he said the teen was holding his hands at his sides as he was walking away from police.

Torres testified he heard Van Dyke continuing to shoot McDonald after he fell down.

“I said, ‘Why the f are they still shooting him when he was on the ground?’” he testified.

Torres’ son gave a similar account of the shooting earlier this week.

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Van Dyke, 40, is charged with two counts of first-degree murder, sixteen counts of aggravated battery, and one count of official misconduct. He could face life in prison if convicted.