Alexander Paffendorf, a California man linked to a 15-year-old girl who fatally shot a teacher and student at a Wisconsin religious school, apologized in court but did not clarify his role.

Authorities say Paffendorf, 20, discussed plans with the shooter, Natalie Rupnow, about attacking a government building with guns and explosives.

Following the Dec. 16 attack, where Rupnow also injured two students before taking her own life, a restraining order required Paffendorf to surrender his firearms.

Though not charged with a crime, he remains under FBI investigation, the Associated Press has reported.

A court hearing on extending the restraining order was postponed, with the investigation expected to conclude in two to three months.

Written by B.C. Begley