WASHINGTON — A Texas militia member was sentenced to more than seven years in prison on Monday, the longest jail term yet for a participant in the January 6 attack on the US Capitol by supporters of former president Donald Trump.

Guy Reffitt, 49, was convicted in March of bringing a gun to Washington, interfering with police and impeding an official proceeding — the certification by Congress of Democrat Joe Biden’s victory in the November 2020 presidential election.

Reffitt, a member of a right-wing militia called the Texas Three Percenters, was also found guilty of obstruction for threatening his teenaged son and daughter if they spoke to law enforcement about his involvement in the attack on the Capitol.

Reffitt’s then 18-year-old son did go to the FBI despite his father’s warning that “traitors get shot” and delivered emotional testimony against his father in court.

US District Judge Dabney Friedrich sentenced Reffitt to 87 months in prison, the stiffest sentence meted out to a Capitol riot defendant so far.

Two men who pleaded guilty to assaulting police officers were sentenced previously to 63 months in prison.

US Attorney Matthew Graves said Reffitt’s sentence “holds him accountable for his violent, unconscionable conduct.”

“Guy Reffitt came to the Capitol on Jan. 6 armed and determined to instigate violence,” Graves said in a statement. “He and others contributed to the many assaults on law enforcement officers that day, putting countless more people — including legislators — at risk.”

Reffitt, an oil industry worker from Wylie, Texas, was the first person to go on trial on charges stemming from the January 6, 2021 attack on Congress.

Dozens of other participants in the Capitol riot have been sentenced after entering into plea agreements.

Video of Reffitt confronting police on the steps of the Capitol and urging on the pro-Trump crowd was played for the jury during his trial.

Prosecutors also displayed text messages from Reffitt in which he promised to drag lawmakers out of Congress “by their hair.”

Reffitt was wearing body armor and a helmet, carrying zip-tie handcuffs and armed with a .40 caliber handgun when he arrived at the Capitol, according to prosecutors.

More than 850 people have been arrested for their roles in the January 6 attack and around 330 have pleaded guilty to various charges.

The storming of the Capitol left at least five people dead and 140 police officers injured and followed a fiery speech by Trump to thousands of his supporters near the White House.

Trump was impeached for a historic second time by the House after the Capitol riot — he was charged with inciting an insurrection — but was acquitted by the Senate.