The historic second impeachment of Trump -- the first trial of a former a president -- and one in which the lawmakers are themselves witnesses to the alleged crime of "incitement of insurrection" continues.

Here are photos of the Jan. 6 attack on the Capitol.

Trump's second impeachment trial -- the first for a former president -- resumes Thursday at noon with a second and final day of opening arguments from House impeachment managers who are making their case that Trump incited an insurrection.

House impeachment managers will provide "additional evidence" of Trump's role in the Capitol riot and his "lack of remorse" on the Senate floor Thursday, aides to the managers' team said on an earlier background call.

"We definitely have the goods and we’ll be bringing them home today," one aide told reporters.

Managers on Wednesday argued that Trump spent months priming supporters to storm the Capitol on Jan. 6, in a last-ditch effort to overturn the election results after failed attempts to compel local, state and federal law enforcement and election officials to do so.

They also used never-before-seen Capitol security footage of senators, House members and former Vice President Mike Pence fleeing the chambers during the riot to transport lawmakers back to that moment when many of them were fearing for their lives.

After the first day's arguments on Tuesday, in an unexpected move, Sen. Bill Cassidy, R-La., joined Democrats and five other Republicans in voting that the trial is constitutional, changing his vote from an earlier motion on the issue, citing the Democrats' "compelling argument."

Democrats would need at least 17 Republicans to side with them in order to convict and potentially bar Trump from running for federal office again, but the majority of Republicans have already signaled they will not vote to convict.

The third day of Trump's second impeachment trial will reconvene at noon on Thursday for the end of the House managers' opening arguments.

House managers have used about five hours and 35 minutes of their time; their aides have told ABC News that they don't intend to use all of their 16 hours of time allotted.

According to those senior aides, the managers are expected to provide "additional evidence" on Thursday of Trump's role in the riot and his "lack of remorse."

"The president knew his vice president was in danger and did nothing," they said.

-ABC News' Trish Turner, Katherine Faulders, Ben Siegel, Rachel Scott, Mariam Khan and Allison Pecorin

Former President Donald Trump is "furious" as he watches the impeachment trial, aides have told ABC News Correspondent Kyra Phillips.

"I'm watching today and seeing everything that was brought forward as evidence and thinking, how are his attorneys going to defend him tomorrow?" Phillips said.

This comes after much of Trump's legal defense team quit shortly before the trial.