Capitol attack: Focus will be on Trump's failure to stop the riot

A congressional panel investigating last year's Capitol riot is expected to argue that Donald Trump did nothing to rein in the mob of his supporters over 187 perilous minutes.

The upcoming primetime hearing is the eighth in a series of public hearings aimed at investigating the events leading up to and during the riot, and determining culpability.

Two former Trump White House insiders - former deputy press secretary Sarah Matthews and ex-deputy national security advisor Matthew Pottinger - are expected to testify.

Additionally, the panel is expected to show videotaped testimony from other officials in Mr Trump's administration to detail what the ex-president was doing during the riot and make the case that he refused to take decisive action to stop it.

Mr Trump has denied any wrongdoing and characterised the committee's investigation as a political witch hunt.

The BBC will have live updates from tonight's hearing, which begins at 08:00 local time (00:00 GMT).

Here's what we know about tonight's hearings and the panel's findings so far.

The primetime hearing on 21 July will largely focus on a period of just over three hours between when Mr Trump finished speaking at a "Stop the Steal" rally at approximately 1300 local time to when he released a videotaped message to his supporters at 16:17 local time in which he asked them to leave the Capitol.

Members of the committee have publicly accused Mr Trump of doing nothing to stop the riot, potentially putting lawmakers - and his own vice-president, Mike Pence - in harm's way.

"We have accounts from people who observed him," one of the panel's members, Virginia Democrat Elaine Luria, was quoted as saying in the New York Times. "There was no concern, anger, distress. He wasn't upset by it."

Although the committee has not commented on tonight's witnesses, they are reportedly planning to include both Mr Pottinger and Ms Matthews. Both resigned immediately following the riot.

In addition to hearing from witnesses, the panel also plans to show outtakes from a video Trump recorded on 7 January in which he seemed to have difficulties condemning the riot.

Over the course of seven hearings over the summer, the panel has sought to connect Mr Trump's repeated - and baseless - claims that the 2020 presidential election was stolen from him to the events of 6 January. They have accused him of an attempted coup to remain in power.

To do so, the panel has leaned heavily on members of Mr Trump's own administration and political allies, which have so far ranged from former White House counsel Pat Cipollone to daughter Ivanka Trump, who told the panel she agreed with the conclusion that there was no evidence of fraud.

One witness, former Attorney General Bill Barr, testified that he at one point feared Mr Trump was "detached from reality".

The panel has also sought to portray Mr Trump's tweets to supporters as a "siren call" to rioters ahead of 6 January.

The former president has previously dismissed the work of the 6 January hearings, writing in June that the committee is "illegally-constituted" and "a kangaroo court".

Ahead of the committee's last hearing on 12 July, Mr Trump accused the committee of unfairly targeting him and dismissed past witness testimonies as "fake and made up stories".

He also repeated his claims of voter fraud in the 2020 election, saying that "there is massive and incontestable evidence and proof".

At the moment, no further committee hearings have been scheduled.

The panel's members, however, have said that they plan to continue their investigation. More hearings are likely in the future.

"This investigation is not winding down," committee member Adam Kinzinger told CBS earlier this week. "We may be towards the end of this tranche of hearings, [but] we may have more hearings in the future and the investigation is still ongoing."