(CNN) There is no doubt that former Dallas police officer Amber Guyger shot Botham Jean in his own Dallas apartment, but prosecutors Tuesday sought to show that she was derelict in her efforts to save him afterward.

Members of Botham Jean's family, (left to right) Bertrum, Brandt, Allison and Allisa Findley, are demanding justice.

The second day of testimony kicked off with Guyger's former colleagues talking about the procedures they followed that night and protocol for shooting investigations.

Officer Michael Lee, one of the first officers on the scene of the September 2018 shooting, described video captured on his body-worn camera that night. He explained it showed him and his partner, Kenan Blair, encountering Guyger down the hall from Jean's apartment.

As Blair walked into the apartment with Guyger, she repeated an assertion she uttered 19 times during her 911 call : "I thought it was my apartment. I thought it was my apartment."

Jean's mother, sister and other family members left the courtroom before the video was played.

'Was that evil of her to do?'

Guyger's defense against the murder charge is that she mistakenly walked into the wrong apartment -- Jean's apartment is on the floor above hers -- thought Jean was a burglar and opened fire, killing him.

She was fatigued after working 40 hours in four days, and was on "autopilot," defense attorney Robert Rogers told jurors Monday. She was not paying attention when she parked in the garage, where the numbers are not clearly marked on the floors, he said.

"Was that evil of her to do? Was that evil of her not to count the floors? Was that just a reasonable reaction to 'Oh my gosh I found a good spot?'" Rogers said.

The prosecution, however, said Guyger, a five-year veteran of the force, missed numerous signs she was on the wrong floor and in the wrong apartment -- including a red doormat, a neighbor's planter, a missing table and clutter on the kitchen counter -- then failed to adequately try to save Jean after shooting him.

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Lee, a six-year veteran who was in the same police academy class with Guyger and knew her, described his counterpart as upset and "very emotional" when he arrived.

The 26-year-old accountant was on the living room floor, alive but unresponsive when police arrived, the bodycam footage showed. Blair immediately began performing CPR as Lee put on blue gloves and tried to stanch the blood coming from Jean's chest wound. Lee took over efforts to resuscitate Jean later in the video.

John Fairleigh, a paramedic with Dallas Fire-Rescue, testified that he and rescue personnel arrived to find police had started CPR on Jean. Rescue personnel took over and continued to perform CPR all the way to hospital, Fairleigh said.

Jean didn't have a pulse. Fairleigh recalled blood spilling out of his wound with every compression.

"It started to pool onto the stretcher," he said. "And as we made our way down the hall, there was a blood trail behind us."

Despite being in the hallway when officers arrived, Guyger has said she provided first aid to Jean, according to an affidavit.

Guyger, who was fired following the shooting, is expected to take the stand when her defense team presents its case.

Prosecutor: Guyger ambivalent after shooting

Tuesday's line of questioning appeared aimed at proving a point prosecutor Jason Hermus made in opening statements Monday: that Guyger was more concerned with her own life and career than she was with the dying Jean.

"When you listen critically to what she is saying, you are going to hear that she is as concerned or more concerned about how this is going to affect her than this poor guy on the floor next to her," Hermus told jurors.

While she was on the phone with a 911 operator, she also sent texts to her partner on the force, with whom she was intimate, saying, "I need you hurry" and "I f***ed up," Hermus said.

While investigators were able to recover those texts, Hermus said, authorities were unable to obtain other messages because Guyger allegedly deleted them in the day or two after the shooting.

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Rather than texting a lover, Hermus said, Guyger should have devoted 100% of her attention to providing first aid to Jean -- or at the very least, comfort.

Hermus also sought to show that Guyger violated protocol by opening fire in the first place.

Jean was on his couch in his shorts, watching TV and eating vanilla ice cream when Guyger walked through the front door, Hermus said.

Under the circumstances, he said, protocol demanded that she take cover and call for backup instead of opening fire -- which Lee confirmed was the normal order of business for police officers in such situations.

Special treatment?

Guyger wasn't the only one to disregard protocol, Hermus said. Her fellow officers did as well -- specifically, Sgt. Breanna Valentine, who left Guyger alone when she was supposed to be separated from the scene and witnesses, and a Dallas police union official who took Guyger out of Valentine's squad car while the investigation was ongoing.

Valentine told Hermus this would not have been normal procedure if the shooting suspect had been a civilian.

Hermus also asked Lee to describe video -- showing Jean on the ground near his couch -- with an indentation in the couch's center cushion and a bowl of food on an ottoman in front of the cushion. Rogers had previously focused on Jean's whereabouts during opening statements.

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Guyger, Rogers said, walked in, looked up and saw what she thought was a burglar about 30 feet from her, Rogers said in opening statements.

"She's thinking, 'Oh my God. There's an intruder in my apartment,' and she's face-to-face with him. She's within 10 yards of him, and he starts approaching her," Rogers said.

She drew her gun, expecting it would make him stop, and ordered him to show his hands, "but he drowns her out and he's yelling, 'Hey, Hey.' And he's 25 feet and then he's 20 feet, and it's happening like this," the attorney said, snapping his fingers.

Guyger "firmly and reasonably believed that she had no choice. She had no options but to use her gun to keep from dying," he said.

Guyger went in and out of Jean's apartment after the shooting, one neighbor said

Two of Jean's neighbors testified they didn't hear any police commands like "Show me you hands" before hearing two gunshots.

One neighbor, Joshua Brown, who met Jean for the first time that day, testified he was down the hall from his apartment when he heard the voices of two people who sounded like they were meeting by "surprise." The gunshots followed "right after," he said.

Soon after, from his apartment balcony, Brown said he saw Guyger come out to the hallway from Jean's apartment on the phone. She was "crying, explaining what happened, what she thought happened, saying she came in to the wrong apartment," he said.

Through his peep hole, Brown said he also saw the former officer "going back, back and forth on the phone."

"And then, I think she went back inside, then came back out," said Brown, who lived across the hallway from Jean.

During testimony, Brown broke down and wiped away tears with his T-shirt. Jean's family members could be heard crying softly.