A jury has ordered conspiracy theorist Alex Jones to pay $965m in damages to families of those killed in the Sandy Hook school shooting.

After a gunman killed 20 children and six members of staff at Sandy Hook Elementary School in Connecticut in December 2012, Jones accused bereaved relatives of being actors who had faked the massacre.

Those giving tearful testimony in a state court included the families of five pupils and three teachers who were killed. An FBI agent who was among the first responders also took part in the legal action.

Some of them hugged after the verdict was delivered. Jones was not present, but video from the courtroom was played on a split screen during his show on his Infowars website.

During closing arguments in the defamation case, lawyers for the plaintiffs said Jones had used lies about the shooting to drive traffic to Infowars and boost sales of various products it offered.

Jones described the case as a “kangaroo court,” mocked the judge, called the plaintiffs’ lawyer an ambulance chaser and said the case was an affront to free speech.

The families endured a decade-long campaign of harassment and death threats by Jones’s followers, lawyer Chris Mattei said.

“Every single one of these families (was) drowning in grief, and Alex Jones put his foot right on top of them,” he told jurors.

Jones’s lawyer, Norman Pattis, claimed during his closing argument that the plaintiffs had shown little evidence of quantifiable losses.

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

Jones has now acknowledged that the shooting did take place.

But he threw the trial into chaos by railing against “liberal” critics and refusing to apologise to the families.

In a similar case in August, another jury found that Jones and his company must pay $49.3 million to Sandy Hook parents. That case was held in Austin, Texas, where Infowars is based.

Jones also faces a third trial, again in Texas, at about the turn of the year.

It is unclear how much he can afford to pay. During the trial in August, he said he could not afford a judgment that exceeded $2m.

However, an economist who testified in Austin said Jones and his company were worth as much as $270m.