U.S. prosecutors charged a Virginia man on Thursday with attempting to aid ultra-hardline group ISIS, including by trying to buy weapons for the militant group and posting support on social media for attacks.

Lionel Williams, 26, was arrested in Suffolk, Virginia, on Wednesday, and made his initial appearance in federal court in Norfolk on Thursday, according to court filings.

Since March 2014, the U.S. Justice Department has charged more than 100 people with ISIS-related crimes.

Williams pledged allegiance to the extremist group in a Facebook post in March 2016, when he declared that it was “time for me to take a stand,” authorities said in court papers.

An informant and an undercover federal agent began communicating with Williams, who eventually contributed money to what he believed would be a fund to help buy military equipment for ISIS, according to authorities. Williams also expressed support for attacks on civilian targets, prosecutors said.

Authorities said Williams purchased an assault rifle online on Dec. 3, 2015, the day after a couple killed 14 people in San Bernardino, California, in a mass shooting that was apparently inspired by foreign militants.

In court papers, a Federal Bureau of Investigation agent said comments that Williams made earlier this week about going to heaven appeared to suggest he “was moving closer to committing an attack that would result in his death.”

Williams’ court-appointed defense lawyer did not immediately comment on the charges.