It looked like an absolutely open-and-shut case. As video footage captured by a bystander clearly showed, Walter Scott was running away from Michael Slager with his back obviously turned on April 4, 2015, when Slager, then a police officer in North Charleston, South Carolina, aimed his gun and shot at the 50-year-old a total of eight times. Even compared with other police shootings of unarmed black men, this one was so gratuitous and so manifestly indefensible that even the local police union declined to pay Slager’s legal fees when he was charged in connection with Scott’s death several days after the killing.

Slager’s criminal trial started one month ago. It came within a hair’s breadth of ending in a mistrial Friday afternoon when the jury foreman informed the judge in the case, Clifton Newman, that the jury could not come to a unanimous verdict. It seems that deliberations had hit a wall because of just one juror, with the other 11 apparently in favor of convicting Slager of either murder or manslaughter.

Typically, that would be the ballgame: a hung jury, a mistrial for the defendant, and the possibility of a second trial. However, after initially telling Judge Newman that the jury was deadlocked, the foreman surprised the courtroom by informing the judge that, actually, they wanted to continue deliberating. The judge allowed them to do so before dismissing court for the weekend. And so, deliberations will resume Monday.

The 12 jurors on the case—six white men, five white women, and one black man—had three options after Slager’s defense rested their case on Wednesday: find the defendant guilty of murder, find him guilty of manslaughter, or find him not guilty of either on the basis that shooting Scott was an act of self-defense.

On Friday afternoon, Judge Newman read out two unusual notes submitted to him by members of the jury. One came from the foreman, and said simply, “It’s just one juror that has the issues.” The second apparently came from that juror, and took the form of a lengthy letter. In it, the juror wrote, “I cannot in good conscience consider a guilty verdict. I respect the position of my fellow jurors, some of which oppose my position. I expect those who hold opposing views not to change their minds.”

The juror continued: “We all struggle with the death of a man and with all that has been put before us. I still cannot, without a reasonable doubt, convict the defendant. At the same time my heart does not want to have to tell the Scott family that the man that killed their son, father, and brother is innocent. But with the choices I cannot and will not change my mind.”

Again, this seemed pretty definitive, and the judge appeared ready to declare a mistrial. Before doing so, however, he had his clerk ask the foreman whether the jury was, indeed, “hopelessly deadlocked.” A note came back saying that they were.

And yet it still wasn’t over. When Newman brought the jury into the courtroom to confirm, in person, that they couldn’t come to a verdict, he asked the foreman—in an apparent last ditch effort to prevent the month’s worth of work he and his staff had just done from going down the tubes—whether further explanation of the law might help the jury come to a unanimous conclusion. That was when the foreman threw his final curveball, replying that it would and keeping these maddening deliberations going.

Even prior to Friday, it has been an unusual trial all around. Earlier this week, Slager took the relatively rare step of testifying in his own defense. He told the jury that he had become scared for his life after pulling Scott over for a broken taillight. That was when, Slager claimed, he entered into a struggle with Scott, at which point the man ran from his car. Speaking with tears in his voice, Slager testified that Scott grabbed his Taser from him during the struggle and pointed it at him, putting the officer in a state of “total fear” and disorientation. “I see him with the Taser in his hand,” he said, according to the Post and Courier. “That’s the only thing I see. … I see that barrel … coming at me, and I knew I was in trouble.” Slager said he made the decision to use lethal force when Scott was just a few feet away from him.

Later, when Slager was asked on cross-examination why he had picked the Taser up off the ground and planted it at Scott’s feet after shooting him—as the video tape of the incident clearly showed him doing—Slager said he could not remember many details of what happened in the moments after he decided to fire his gun. “I don’t know why I dropped it on the ground,” he said, noting that he picked the Taser back up a few seconds later. Reflecting on his anxious state in the heat of the moment, Slager memorably testified, “My mind was like spaghetti.”

The stakes in the Slager case have always been stark: as the New Yorker’s James Surowiecki put it on Twitter on Friday after news broke that the jury was deadlocked, “If a jury can’t convict under these circumstances, what will it take?” Put another way: If even Slager’s actions can be successfully defended in court, it’s hard to imagine a police officer ever being held accountable for killing someone in the line of duty.

The reasons for this are multiple, but chief among them is that the laws governing police use of force tend to be impossibly vague and flimsy. Back in November, while the prosecution was still in the midst of presenting its case against Slager, I wrote that the law in South Carolina is particularly complicated because the state doesn’t even have a formal statute that defines the circumstances under which police officers are legally allowed to use lethal force. Instead, judges, prosecutors, and defense attorneys in the state must look to a 2004 ruling from the South Carolina Supreme Court—one that is based on an utterly incoherent interpretation of a so-called common law standard that says police can use any amount of force, including deadly force, to “seize” a fleeing felon if necessary. Inevitably, experts told me, jurors are left confused when trying to determine an officer’s guilt or innocence.

As it turned out, none of that really mattered in the Slager trial, as the defense team argued that Slager acted in self-defense, and did not technically ask the jury to give his status as a law enforcement agent any special consideration in evaluating the legality of his actions. Slager used lethal force the way any reasonable person might have done in the same situation, the defense argued, and he would deserve acquittal regardless of whether or not he had been carrying a police badge at the time.

If Slager ends up walking, expect his defenders to say he was treated the same way under the law as anyone else would have been. And yet, it’s hard to explain away the fact that we’re headed toward Day 4 of jury deliberations over the guilt or innocence of a man who fired eight bullets at someone who was running away from him, was caught on video while doing it, and appeared to plant evidence on his victim before thinking better of it. The particulars of Slager’s legal defense notwithstanding, it’s hard to imagine this case would have ever gotten past the plea bargaining phase if the defendant was anyone but a police officer.