The Ohio mass shooter attended an Antifa rally in May armed with a gun similar to the one used during the subsequent massacre in Dayton.

Betts, who killed nine people outside a nightclub on Saturday, attended an anti-KKK event on May 25 armed with a gun "which appeared to be similar in style to the one used in Sunday's shooting," local Ohio news outlet WHIO reported.

The gunman used a semi-automatic pistol during the attack that police say was modified to act like a rifle.

The shooter also "wore a bandanna covering part of his face and sunglasses," during the protest, which is stereotypical Antifa garb.

Betts was likely alerted to the rally by far-left Antifa doxxing account called Antifash Gordon, according to a report by Big League Politics.