A Northern Virginia attorney was arrested Thursday in Miami and accused of coercing underage girls into sexual activity.

Matthew Erausquin, a founding partner of the firm Consumer Litigation Associates’ Northern Virginia affiliate, is charged in Alexandria federal court with sex trafficking involving six minors. Erausquin has not yet been appointed an attorney.

“We are still processing all that we have learned,” Consumer Litigation Associates said in a statement. “We are saddened and will remain bewildered now and maybe forever.”

According to an affidavit from a Fairfax County detective, the investigation began last year, when a 17-year-old high school student approached local police to say friends of hers had been paid for sexual activity with a man in his 40s. She said one friend was given $1,000 and a handbag; another a camera and marijuana.

Police say they eventually identified Erausquin through cellphone, credit card, Uber and PayPal records showing he had communicated with the girls, sent them cash and bought them first-class plane tickets, expensive cameras and luxury handbags. Victims later told police he also gave them illegal drugs.

Prosecutors say Erausquin met one victim on Seeking Arrangement, a website geared toward wealthier older men looking for younger partners who need financial help. Others were the student’s friends or met him on Tinder, where he pretended to be 18, according to the affidavit.

While some victims falsely told him they were 18, according to the affidavit, when one told him the truth, she said he “indicated . . . that he kind of knew their ages the entire time and liked it.” One 16-year-old told police it was “obvious” she and a friend who met Erausquin were not adults. He would pick up or drop off victims at school, prosecutors said.

One girl alleges that she passed out after taking a hit of marijuana at Erausquin’s Arlington apartment, then woke up with no clothes on. Another who had moved across the country said Erausquin bought her a plane ticket home but threatened to cancel her return flight when she did not come see him.

When two victims threatened to go to the police if he did not pay them more money, according to the court record, he said he would sue them and that extortion was a more serious crime than having sex with a minor.

Erausquin is set to appear Monday in court in Florida, where authorities will seek to return him to Virginia to face trial.

Erausquin has been separated from Consumer Litigation Associates and taken off all cases, the firm said, and an independent ethics counsel was hired “to assist in ensuring and confirming that the allegations as to Matt’s personal life remain disconnected from any of the work and operations of this law firm.”