Police arrested and charged a man suspected of involvement in a stabbing after a rally for supporters of President Trump in Washington, D.C., on Saturday. Phillip Johnson, 29, is charged with assault with a dangerous weapon, according to the Associated Press. The stabbing occurred outside Harry’s Bar, a known hangout spot for the far-right extremist Proud Boys group. Four people were stabbed, with one of them identifying Johnson as their assailant, according to a police report obtained by the AP.

Members of the Proud Boys—and fellow supporters of President Trump—attended the rally on Saturday night. It turned violent fast, as attendees vandalized Black churches and tore down Black Lives Matter signs, setting one on fire. All in all, Washington, D.C. police arrested nearly 30 people in connection with Saturday night’s violence, with charges including assault, weapons possession, resisting arrest, and rioting, per the AP.