Alexander Paffendorf was detained late last month after FBI agents said he was plotting a mass shooting with Natalie "Samantha" Rupnow.

Alexander Paffendorf expressed regret for his involvement in court on Friday without explaining his precise role.

A Carlsbad man who authorities say communicated with a Wisconsin school shooter appeared in a San Diego courtroom on Friday.

Alexander Paffendorf appeared in court for a gun violence restraining order. The hearing was continued to April to allow time for investigation.