The judge in the murder trial of a white former South Carolina policeman accused of shooting an unarmed black suspect in the back declared a mistrial Monday after the jury said it was deadlocked. The case was one of several fatal shootings of black suspects across the United States that have thrown the spotlight on how police use deadly force – and whether a suspect’s race leads to bias in that decision. The jury had indicated on Friday that it was within one vote of returning a guilty verdict against Michael Slager in the killing of Walter Scott after the 50-year-old fled a traffic stop and struggled with the officer on April 4, 2015 in North Charleston. Lawyers for Slager – who could have been convicted of either murder and voluntary manslaughter – argued that Scott’s disregard for authority, aberrant behaviour and aggressive actions justified the deadly encounter. “I so declare this case a mistrial,” Judge Clifton Newman told the court in the historic port city of Charleston. “We’re back to square one.” The jury – which had been locked in deliberations since the middle of last week after a month of testimony – ultimately said on Monday it was unable to reach a unanimous decision “despite the best efforts of all members”. More US police shootings are being caught on camera - but that doesn’t mean you’ll see them Newman had pleaded for the panel to come to a decision, saying a mistrial would only mean a new trial with the same evidence argued in front of different jurors. Prosecutors have said they will retry the case. Scott family attorney L. Chris Stewart called the mistrial a “missed opportunity to heal a lot of wounds in this country”. His colleague Justin Bamberg added: “We all know that it’s difficult to convict law enforcement officers in this country. But every case is different. I don’t believe there is a person with a soul who believes what Michael Slager did is OK, or not wrong.” “I don’t think questions of fact were the issue for this jury. I think the issue was interpretation of the law ... I don’t think we’re going to have this problem next time.” California policeman placed on leave for allegedly tickling dead suspect’s feet “Officers need to know you can’t do these things and at the end of the day when Michael Slager is convicted, that message is going to ring loud and clear,” Bamberg added. Slager also faces trial in federal court next year on charges of violating Scott’s civil rights. North Charleston, which borders Charleston, has a history of strained race relations between the city’s police department and large black community. Scott’s death had set off protests in the area, but on Monday, his brother Anthony urged would-be protesters to remain peaceful. US admits it must do more to uphold civil rights after police killings of unarmed black men Much of the trial focused on a single piece of evidence: a bystander’s video that captured a portion of the struggle, Scott’s attempt to flee and Slager firing eight shots at the suspect, five of them hitting their mark. The 34-year-old Slager has said he feared for his life when he tried to subdue the suspect, alleging that Scott grabbed his stun gun and charged at him. On Friday, confusion reigned in the courtroom -- jurors first asked to rehear testimony from Feidin Santana, who made the video and was the lone eyewitness to the encounter between Slager and Scott. Santana had disputed Slager’s account of the struggle, saying Scott never charged at him, and was only attempting to flee the policeman’s grip. But only 12 minutes later, the jurors said they did not need to review the testimony and that they could not reach a consensus. It appeared the jury had just one holdout. Newman ordered the jury to try again. ‘He was out of control’: Texas cop filmed pulling gun on teens at pool party resigns “I’m not sad,” Scott’s mother, Judy Scott, told reporters in an emotional address. “I know that justice will be served.” “I don’t care what men say. I don’t care how it looks,” she said. “It’s not over. You all hear me, it’s not over ‘till God says it’s over.” Slager had faced a sentence of 30 years to life imprisonment if convicted of murder. The manslaughter charge carried a sentence of two to 30 years.