Are His Parents Responsible? A Mass Shooter’s Mother Goes on Trial.

The trial of Jennifer Crumbley, whose son carried out the worst school shooting in Michigan history, began on Thursday with dueling portraits: one of a mother whose negligence was so extreme that it caused a tragedy, and another of a good, even “hypervigilant” mother who was in the dark about her son’s troubles until that tragedy unfolded.

These starkly different images were presented to jurors in a courtroom in Pontiac, Mich., about 20 miles south of Oxford High School, where the mass shooting took place on Nov. 30, 2021.

While the case centered on a momentous legal question — whether parents should be held criminally liable for violent crimes committed by their children — the horror of that day in Oxford hung over the first day of testimony in the trial. School employees, including one who was shot in the arm, testified of the terror they experienced, and surveillance videos of the shooting were played, showing some of the victims.

The shooter, Ethan Crumbley, who was 15 at the time, killed four students and injured seven others. He pleaded guilty to 24 charges, including first-degree murder, and was sentenced last month to life in prison without the possibility of parole.

The cases against Ms. Crumbley and her husband, James Crumbley, are at the leading edge of a push by some prosecutors to hold parents accountable when they are suspected of enabling deadly violence by their children. Just in the last few months, parents whose children carried out gun violence in other states have pleaded guilty to charges of reckless conduct or neglect.

In the Michigan trial, Ms. Crumbley, 45, faces more serious charges: four counts of involuntary manslaughter. Prosecutors say that despite glaring signals of Ethan’s violent intentions, his mother’s failures to take “just ordinary care” to act on what she knew made her criminally liable for the carnage at Oxford High School. In charging her with manslaughter, they are arguing that her behavior was “a cause” of the killings.

Mr. Crumbley, 47, has also been charged and will be tried separately in March. Unable to post a combined $1 million bail, both parents are being held in the Oakland County Jail.

Many facts of the case had already become public in court filings leading up to the trial. Days before the shooting, Mr. Crumbley took Ethan to buy a 9 millimeter SIG Sauer handgun and Ms. Crumbley took him for target practice. On the morning of Nov. 30, both parents were called to the school because Ethan had drawn violent images on some class work, including a gun similar to the one his parents had just bought, the figure of a shooting victim and the words “Blood everywhere.” Against the suggestion of a school counselor, the Crumbleys did not take their son out of school to get immediate medical help, and they were unaware that he had taken the gun to school in his backpack that day.

Within hours of that meeting, Ethan began shooting.

In his opening statement on Thursday, Marc Keast, an Oakland County prosecutor, emphasized that Ms. Crumbley was not charged with murder, nor was she simply accused of being a bad parent. But, he said, because of her “willful disregard for the danger that she knew of,” she was a cause of the mass shooting that Ethan carried out.

“Jennifer Crumbley didn’t pull the trigger that day,” Mr. Keast said. “But she is responsible for those deaths.”

Mr. Keast spent much of his opening statement describing the litany of troubling signals leading up the shooting — signs of a “deteriorating mental crisis” that he said Ms. Crumbley knew of but did not share with the school — while suggesting that prosecutors would also highlight Ms. Crumbley’s actions in the aftermath. After Ethan’s arrest, the Crumbleys fled the area, and the police later found them in the basement of a Detroit art studio.

“Her first instinct was to lie,” Mr. Keast said. “Her second was to run.”

Shannon Smith, a lawyer representing Ms. Crumbley, said the prosecution was trying to lay blame for a heinous attack on a woman who “did the best she could” in raising her son.

Ms. Smith said Ms. Crumbley learned only after the shooting about many of the alarming signs, such as Ethan’s text exchanges with friends, that the prosecution would point to as evidence of Ethan’s mental descent. Ms. Smith said that Ethan hid these signs from his mother and that school officials had never told her about some of the more troubling instances of Ethan’s behavior.

“He did something she could have never anticipated or fathomed or predicted,” said Ms. Smith, who also told the jury that Ms. Crumbley would take the stand.

Ms. Smith insisted that the Crumbleys went to Detroit after the shooting because they were facing death threats and that they had planned to turn themselves in after learning they were facing charges.

After the opening statements on Thursday, the prosecution called its first witnesses, beginning with a teacher and an assistant principal who were at the high school the day of the shooting. As surveillance video was played in the courtroom, the witnesses described the chaos and violence that unfolded, sometimes breaking down in tears.

The final witness of the afternoon was Special Agent Brett Brandon of the Bureau of Alcohol, Tobacco, Firearms and Explosives, who responded to the shooting. Through Mr. Brandon’s testimony, as well as Facebook messages, Instagram posts and surveillance videos introduced as evidence, the jury learned how Ethan’s parents took him to buy firearms, including the one used in the shooting, and brought him to the firing range multiple times. Mr. Brandon also testified that the guns, which were not registered, did not appear to be very securely stored in the Crumbley home.

The most heated exchange of the day came during a midmorning recess after the jury was sent out of the courtroom for a break. Ms. Crumbley had been sobbing audibly as the videos of the shooting were played. Prosecutors complained to the judge, Cheryl A. Matthews, that the defense was not abiding by the instructions to keep emotions in check during the court proceedings. Ms. Smith, the defense lawyer, responded that the videos were horrific.

Judge Matthews counseled patience.

“Everyone here is human,” she said. She emphasized that she was trying to run a fair trial, and that if people found things too excruciating to bear, they should leave the courtroom.

But, she added: “I’m not a robot. I’m trying to keep myself from sobbing. I’ll do it at 6 o’clock tonight.”