Five East Jerusalem teenagers were acquitted on Wednesday of throwing rocks and firebombs - but only after having spent a year and a quarter in jail or under house arrest.

The teens, all aged 15 to 18, were charged with having participated in disturbances of the peace in East Jerusalem's Silwan neighborhood in March 2011. According to the indictment, the boys joined several other Silwan residents in throwing rocks, firebombs and firecrackers at the homes of the neighborhood's Jewish residents and at members of the security forces. While most of the firebombs hit the walls of houses or cars and bounced off, one seriously injured a Border Police officer when it exploded on the pavement between his legs. He suffered severe burns and needed prolonged medical treatment.

A few days later, the boys were arrested on the basis of testimony by A. and M. - two other East Jerusalem residents who had been arrested a few days earlier, confessed to participating in the riot and then implicated the others. M. claimed to have seen four of the boys at the riot, while A. incriminated the fifth.

Later, the two men retracted their statements, but the prosecution nevertheless decided to indict the five teenagers on the basis of what A. and M. originally told police. The indictment charged them with manufacturing weapons, intentionally causing severe injury and aggravated assault against a policeman.

The boys claimed they were nowhere near the scene of the riots at that time. But the Jerusalem District Court ruled that the three older boys would stay in jail until the end of the trial, while the two younger ones would remain under house arrest.

During the trial, however, significant contradictions emerged between the testimony of A. and M. "There were contradictions in their statements - both regarding the description of events and regarding when they happened," wrote Judge Yoram Noam in his verdict.

Moreover, Noam said, in cases where the interrogations were recorded, there were numerous discrepancies between the recordings and the summaries later written up by police.

In some cases, there were no recordings and in those instances the police prepared "transcripts" that were very partial and misleading, he said, because they didn't include the actual questions and answers at all. They merely summarized them.

Consequently, Noam wrote, it's impossible to dispel suspicions that police interrogators were leading the witnesses.

"We can't rule out the possibility that the interrogator told M. the suspects' names and encouraged him to incriminate them by pretending that they had incriminated him, and that if he did incriminate them he would improve his own situation," the verdict said.

The Jerusalem District Prosecutor's Office said it is studying the verdict and will consider whether or not to appeal it. Attorney Nir Adelby, one of the five public defenders appointed to represent the teenagers, said the boys' families are considering suing the state over their prolonged detention.