Brother of Capitol officer who died after Jan. 6 riot blasts Republicans and Trump in letter

The brother of fallen Capitol Police officer Brian Sicknick, who died shortly after defending the Capitol on Jan. 6, 2021, has sent a scathing letter to Republican leaders, accusing the party of choosing "lies and deceit over truth" more than two years after a violent mob of Trump supporters stormed the Capitol.

"Instead of being a wake up call for our nation to reflect on what unites us as a country, the Insurrection simply widened the divide we have among our people. It has become a war cry for the Republican Party to tear down anything or anyone that challenges their views on any subject," Craig Sicknick wrote in the letter obtained by ABC News.

Sicknick said his family continues to be deeply affected by the death of his brother, Brian, who was brutally attacked by rioters, video shows. The 42-year-old military veteran, who worked for the Capitol for 12 years, died a day later after suffering two strokes.

A D.C. medical examiner ruled Officer Sicknick died of "natural" causes. According to the medical examiner, a stroke is specifically what caused Sicknick's "natural" death, but the events of Jan. 6 may have contributed.

Some Republicans have pushed back on the Capitol Police's classification of Officer Sicknick's death as a line-of-duty death. Craig Sicknick addressed this in the letter, but didn't mention any of those Republicans by name.

"His death was due in large part to the actions of Mr. Trump and his misguided cultists who, on that fateful day, attacked the United States Capitol with the full intent of doing serious harm to Members of Congress, even many Republicans unless they threw out over two centuries of precedent and illegally overturned an election," Craig Sicknick stated.

The letter, addressed to all members of the Republican Party, was sent directly to congressional leadership: Speaker of the House Kevin McCarthy and Senate Minority Leader Mitch McConnell. It calls out what he says are repeated attempts to downplay the insurrection on Jan. 6.

Trump's actions on Jan. 6 led to a slew of resignations within his own administration and prompted bipartisan outrage.

In the immediate aftermath of the attack on the Capitol, McCarthy said former President Donald Trump "bears responsibility" for what happened. Weeks later, McCarthy visited Trump at Mar-a-Lago in Florida and posed for a picture together. McConnell rebuked Trump, insisting he provoked the mob on Jan. 6. However, McConnell did not vote to find the former president guilty of inciting the insurrection during the Senate impeachment trial.

"Many people in leadership positions in the Republican Party dutifully supported Trump in his efforts, whether actively, or, more often, passively by not calling out criminal behavior. This is in spite of their own lives being threatened during the Insurrection," Sicknick wrote.

"Some actually called Trump out on it, for a moment, before traveling to Mar-a-Lago and then suddenly had a change of heart. (Sound familiar Mr. McCarthy?) Funny how such things work in the swamp that Trump claimed he would drain, but actually deepened substantially," Sicknick added.

Representatives for McCarthy and McConnell did not return ABC News' request for comment.

In August, Trump was indicted for his alleged efforts to overturn the 2020 election. The sweeping indictment alleges Trump undertook a targeted "criminal scheme," knowingly fueling lies to block the nation's process of collecting, counting and certifying the results of the presidential election in order to stay in power. Despite multiple federal investigations, the former president has remained a dominant force in the party as the front-runner for the Republican nomination. Trump has denied doing anything wrong, has entered a not guilty plea and has said the charges are politically motivated.

"How much evidence does one need before making a decision that it is well past time to move on from Trump and his lackeys and move the party past this very dark time? The 60+ failed legal challenges to the election results, many in courts run by Trump appointees, wasn't enough evidence? How does a party go from being one of overall integrity to one that, for all appearances, should meet under a big top circus tent instead of in the hallowed halls of the United States Capitol Building," Sicknick wrote.

In 2021, Officer Sicknick's mother lobbied Republicans to establish a bipartisan independent commission to investigate the attack. The effort was blocked by Republicans in the Senate.

Months later, Officer Sicknick was awarded posthumously a Congressional Gold Medal for giving his life to protect the Capitol on Jan. 6 -- an effort a number of House Republicans voted against.

At the ceremony, Sicknick's family refused to shake the hands of Republican leaders McConnell and McCarthy.

"The party claims it is pro law enforcement, but the actions of its leadership speak far louder than the false words they spew. The same party claims to maintain a higher moral ground than their opposition, but continuously shows that they are not capable of taking the high road," Sicknick wrote in the letter.

He ended the letter with a warning about a party that continues to support Trump.

"Continued worship of a seriously flawed narcissist who has called for the suspension of parts of the Constitution, at least when it suits him, will lead us to a very dark place for our nation, a place from which we may not recover."

Thirty-two months after the mob laid siege to the U.S. Capitol assaulting roughly 140 officers, more than 1,106 defendants have been charged.