Mauricio Morales-Caceres, left, was convicted of first-degree murder in the stabbing and slashing death of Oscar Navarro, right, in Navarro’s Silver Spring, Md., townhouse (Courtesy of Montgomery County State’s Attorney’s Office and the Navarro family)

By the first afternoon of the trial, one juror wondered how much more she could take.

“She is a school teacher,” Montgomery County Circuit Judge Mary Beth McCormick told prosecutors and defense attorneys, with the jury out of the courtroom. “She is picturing her schoolkids’ faces superimposed on the decedent’s body.”

The horrified reaction of Juror 223 last week was an understandable response to incomprehensible images: crime scene and autopsy photographs depicting the gruesome murder of Oscar Navarro, 36.

“Maybe you could lean away from the pictures with the face,” McCormick told prosecutors.

In the end, prosecutors were allowed to show jurors eight of the most disturbing photos — a key to their obtaining a ­first-degree murder conviction Friday against Mauricio Morales-Caceres, 24.

A 24-year-old man was convicted of first-degree murder Friday in the stabbing and slashing death an acquaintance at least 89 times. He faces life in prison without parole. Hear the 911 call made when Navarro’s body was discovered. (Montgomery County State's Attorneys Office)

In December 2014, armed with a 15-inch butcher knife, Morales-Caceres stabbed and slashed Navarro at least 89 times in the basement of Navarro’s townhouse in the Bel Pre area of Silver Spring.

“The defendant took the knife and sawed,” prosecutor Douglas Wink told jurors during closing arguments, standing next to a large image of the body of Navarro on his back in his basement. “This man reached in with his bare hands and took out his liver. He probably thought it was his heart. He ripped out his liver and left it on his chest for the police to see.”

By then, some jurors were no longer looking at the images. Those who did wore blank expressions.

Their pain, of course, fell far short of the anguish of Navarro’s relatives in the courtroom. For them, the photos had the power to overwhelm memories they were trying to cherish: Oscar playing with his two children, Oscar dancing, Oscar being what his boss at Joe’s Stone Crab called a “model employee” as a busboy.

“You can’t believe your eyes, what you see,” Navarro’s brother Nelson said after the verdict. “I don’t understand how one human being can do that to another. It’s like he was possessed by demons.”

Prosecutors never could establish a strong enough motive in the case to present one to the jury. To show the killer persisted in the slaying — a form of premeditation that made the murder punishable by life in prison — prosecutors relied on forensic evidence and the photographs to present the sequence of the injuries.

The attack, they said, started on Navarro’s back, and moved to his face, head and chest. The details proved how many times Morales-Caceres could have halted the assault.

Mauricio Morales-Caceres, who was convicted of first-degree murder in Montgomery County, shown here after his arrest in 2014. (Courtesy of Montgomery County State's Attorney’s Office)

Before the trial began, defense attorney Ron Gottlieb tried to halt prosecutors’ plans to show photos to the jurors. When he couldn’t do that, he was forced to address the subject of the images during his opening statement Tuesday.

He asked jurors to “put the emotional impact of the crime scene, the blood and everything else to the side.” He stressed that for all of their gore, the photographs didn’t show what may have precipitated the attack and certainly didn’t show who did it.

Gottlieb suggested that Navarro had angered the wrong crowd but not his client.

“There is a big injustice going on here,” Gottlieb said. “People were out to get him, and it wasn’t Mauricio.”

But prosecutors had a staggering wealth of evidence tying in Morales-Caceres. Prosecutor Steve Chaikin took jurors through those details. He began by warning them about photos they would see.

“It’s not easy. It’s not easy at all to talk about murder and death,” he said. “As a matter of fact, most people, most citizens, most jurors will not have to see the pictures and hear the things that you’re going to hear over the next several days. This was a gruesome murder.”

Chaikin acknowledged he did not know why Morales-Caceres killed Navarro. He said that ­Morales-Caceres knew him, called him before coming over and was undoubtedly let inside a townhome where Navarro lived alone. At some point, the two were in the basement, where Morales-Caceres attacked.

Later, Navarro’s estranged wife went to the house, found his body and called 911. Investigators found a bloody palm print and bloody shoe prints. A few days later, they matched the print to Morales-Caceres.

Police went to his house. He was wearing a pair of white Nikes that matched the bloody shoe prints. He was carrying a cellphone that showed repeated calls to Navarro’s number, calls that stopped around the time Navarro was killed. Inside Morales-Caceres’s bedroom, detectives found the butcher knife with Navarro’s DNA on it.

Chaikin then turned his account to the crime scene, using photographs to lay out how long and brutal the attack was.

It was later that day, during a break, that one juror approached the judge’s law clerk and discussed her anxieties over the photos.

That discussion was disclosed in open court, outside the jury’s presence. The judge told the lawyers that the juror taught children who were of similar ethnicity to the defendant and the victim, and that was leading her to see those children’s faces when she viewed the stabbing photos.

The attorneys said the teacher had indicated during the selection process for the jury that she wouldn’t be swayed by gruesome images. But the judge was sympathetic to her reaction.

“You don’t know until you see it,” McCormick said, “because you can’t fathom the nature of the pictures. . . . I’ve never seen pictures of this ilk.”

Wink, a prosecutor, argued the photos were critical in laying out the crime. “We all live in the real world where bad things happen, and this one of them,” he said.

The defense attorney, Gottlieb, renewed his request to remove the photos from the trial. McCormick said she would consider doing so.

The jury returned to the courtroom and the judge spoke to them.

“I know the pictures have been very graphic,” she said. “But there aren’t going to be any more graphic pictures, unless absolutely necessary — certainly no more today.”

As the trial went on, the school teacher wasn’t the only juror affected. During a break, a 47-year-old federal worker went to the courthouse cafeteria to get a cup of coffee. In a daze, he walked past the cashier without paying.

“I was kind of shocked,” he said in an interview after the trial, speaking on the condition of anonymity to maintain his privacy. “A horror movie couldn’t do it justice. This was beyond a film.”

On Thursday, just before the medical examiner was set to testify, the judge again spoke to the lawyers, without the jurors present, about which autopsy photos she would allow to be shown during the medical examiner’s testimony and during closing arguments.

McCormick said she would permit six to be used.

“There are times when photographs have to be admitted to allow the jury to visualize the atrociousness of the crime,” McCormick said, putting it in legal terms: “They are probative as to the issue of intent.”

The jury reached its verdict Friday, concluding that Morales-Caceres was the killer and that he acted in willful premeditation. He is set to be sentenced this summer.

Prosecutors have said they will ask for life in prison with no chance of parole. Should ­Morales-Caceres ever get out of prison, every indication is that he would be deported to his native El Salvador.

Prosecutors earlier said he entered the United States illegally. And since his stay at the Montgomery County jail, immigration officials have lodged a detainer on him, an indication they would move to have him deported at the end of a prison sentence.

Nelson Navarro, Oscar’s brother, said he has turned his attention to Oscar’s 12-year-old son and 8-year-old daughter. They know their dad was killed, but so far the family had been able to spare them details of how he died. During the trial, they came to the courthouse on one day but stayed in the prosecutor’s offices. Their mother watched the trial in the courtroom.

“The only thing we can do for the family,” Nelson Navarro said, “is get closer to them.”