The United States is bracing for a second night of protest across major cities in the wake of the grand jury decision not to indict police officer Darren Wilson for the lethal shooting of black teenager Michael Brown in August in Ferguson, near St Louis, Missouri.

Uproar and rage greeted the announcement of the decision not to prosecute, which was released at 8pm last night. Ferguson immediately erupted into demonstrations, looting, torching of buildings, the firing of hundreds of gunshots, and 80 arrests. There were also major and more peaceful protests in New York, Oakland and a dozen other cities, with roads and bridges being blocked in protest.

That the grand jury would decide not to indict had been widely, quietly expected by political and legal commentators — as grand juries rarely refuse to indict civilians (refusing only 50 of 69,500 cases referred to them) but almost always refuse to indict cops involved in lethal killings (80 in 81 times).

But the impression had been given, or taken, that Wilson was likely to be indicted. Wilson had got into an altercation with Brown on a street in Ferguson. Wilson claims that Brown grabbed for his gun, that Wilson shot at him once and chased after him. He claims Brown turned and charged at him, and that he then loosed off a further 10 shots, the rest of his clip, hitting Brown several times and killing him. Witnesses who spoke to the media in the weeks following the shooting said Brown had had his hands up when he had turned towards Wilson and was trying to surrender.

When the announcement came, the crowd gathered in Ferguson howled in outrage. Brown’s parents called for calm. However, Brown’s stepfather told the crowd to “burn the bitch down”. They took him at his word, torching a dozen shops along the main street, including a Walgreens chemist and a Little Caesars pizza, the only time their goddamn pizzas have been warm.

The police in Ferguson were outnumbered, and the National Guard had only belatedly been called, hence the protesters/rioters/looters had the run of the place for a few hours. The decision of the prosecutor to release the finding at night was met with widespread disbelief and a great deal of suspicion. Was it based simply on internal office timing — the jury had delivered its verdict at 1pm — or was it designed to foment riot and looting from criminal elements within, rather than a daylight peaceful protest more likely to embarrass the St Louis police?

The public statement by prosecutor Bob McCulloch did nothing to reassure anyone about the process. Prosecutors are charged with getting an indictment from grand juries, who are not passing judgement on the case, but only on whether there is probable cause to indict. Prosecutors run grand juries — those up for indictment have no right to defence counsel. Any prosecutor steers a grand jury through a path to indictment. In this case, the prosecutor dumped all the evidence on the jury. Sixty witnesses in all were called, some of whom had been already discredited by forensic evidence, with the result that the jury got an overwhelming amount of material to deal with.

Whether the forces around Michael Brown’s family — which had included a bevy of high-class activists including Al Sharpton and Cornel West — had made a strategic decision to wait for the decision and then act, or it had simply happened that way, the process has not added to political clarity. The grand jury process, in which white prosecutors and cops working together must then investigate each other, was hopelessly compromised from the start. Waiting on its decision conferred legitimacy on it, when there was no real chance that it would deliver the result activists wanted.

The crucial and ill-explained event in the shooting remains obscure. After Wilson gave chase, Brown, already wounded and unarmed, turned around. He either moved towards Wilson in surrender or threateningly, the latter an unusual move (forensic findings showed no drugs in his body, which might have affected his judgement). It was while he was moving forward, from many metres away, that Wilson filled him with bullets. It seems hard not believe that had more to do with rage, anger and arrogance than legitimate self-defence.

But the only other recourse — a federal prosecution of Wilson for violating Brown’s civil rights (!) — demands a yet-higher standard of proof than a manslaughter indictment. The Attorney-General would have to approve it, and currently, there isn’t one, with the latest nominee waiting for approval from a recalcitrant Republican Senate.

The disturbance prompted President Barack Obama to give a speech, far from his best, in Chicago earlier today, saying, well, I couldn’t get much of a read on it above platitudes tbh, and I’m sure a lot of the people felt the same. The day before, he’d made a far more terse statement saying “we are a nation of laws, and the grand jury has made its decision”, making it pretty clear that the fix was in. Darren Wilson gave an interview saying he’d do it all again the same. Twelve bullets. An unarmed kid at a distance. There is no justice, hopefully there’ll be no peace.