The far-Right conspiracy theorist Alex Jones was on Wednesday ordered to pay nearly $1billion in damages to the families of the victims of the 2012 Sandy Hook school shooting for falsely claiming the massacre was a hoax.

The $965m compensation decision was reached by a jury following a three-week civil trial in Waterbury, Connecticut, not far from where a gunman killed 20 children and six staff members at Sandy Hook Elementary in the deadliest school shooting in US history.

Lawyers for families of eight victims during closing arguments last week said Mr Jones cashed in for years on lies about the shooting, which drove traffic to his website InfoWars and boosted sales of its various products.

InfoWars could be pushed to declare bankruptcy if forced to pay the full amount – one of the highest defamation awards in US history.

Mr Jones, 48, peddled false stories for years, claiming the massacre was staged as part of a government plot to take away Americans’ guns, that it was a “false flag” attack, and that the parents of the victims were “crisis actors.”

The families suffered a decade-long campaign of harassment and death threats by Mr Jones’ many millions of followers, attorney Chris Mattei said. Mark Barden, who lost his son Daniel, said Jones’ supporters verbally attacked him and even chased him while screaming that he was a liar. He also testified that his son’s grave was vandalised.

“Every single one of these families (was) drowning in grief, and Alex Jones put his foot right on top of them,” Mr Mattei told jurors. Another attorney, Norman Pattis, urged them to ignore the political undercurrents in the case.

“This is not a case about politics,” Mr Pattis said. “It’s about how much to compensate the plaintiffs.”

The trial was marked by weeks of anguished testimony from the families, who filled the gallery each day and took turns recounting how Mr Jones’ lies about Sandy Hook compounded their grief. An FBI agent who responded to the shooting is also a plaintiff in the case.

Mr Jones, who has since acknowledged that the shooting occurred, also testified and briefly threw the trial into chaos as he railed against his “liberal” critics and refused to apologise to the families.

The case presented the greatest financial risk to Mr Jones, because he was found liable of violating Connecticut’s Unfair Trade Practices Act and there is no cap on punitive damages under that law.

It came two months after another jury found that Mr Jones and his company must pay $49.3 million to Sandy Hook parents in a similar case in Austin, Texas, where the headquarters of Infowars is located.

Mr Jones’ lawyers have said they hope to void most of the payout in the Texas case before it is approved by a judge, calling it excessive under state law. He has a third Sandy Hook damages trial pending stemming from a defamation suit he lost.