SAN DIEGO (KGTV) A retired FBI agent wonders if the 15-year-old Wisconsin school shooter was using a video game or online chat room when she met a Carlsbad man, who has been detained for plotting a separate mass shooting.This situation is really unusual that you had two people from across the country plotting separate and distinct events all on their own, said Bobby Chacon, in an interview from Port Richey, Florida.Police detained a 20-year-old man in Carlsbad Tuesday night and alleged in an emergency gun violence restraining order he was going to commit a mass shooting.Government building targeted The man admitted to FBI agents he told (Natalie) Rupnow he would arm himself with explosives and a gun and would target a government building, a Carlsbad police officer wrote in the court filing.Rupnow, who also went by Samantha, is the now-dead 15-year-old girl who opened fire and killed a teacher and student on Monday at Abundant Life Christian School in Madison, Wisconsin. ABC 10News is not naming the Carlsbad man at this time because he has not been arrested or charged with a crime.I'm not really surprised charges haven't been filed. I'm sure they're looking at that very closely. It takes a little bit of time, said Chacon, who spent 27 years in the FBI.He said the gun violence restraining order is a quick legal remedy that allows police to remove guns from someone.Chacon believes the Carlsbad man and the school shooter, who killed herself after opening fire on others at her school, probably had like-minded ideologies and hated the same people, which gave them common ground for their problems.The FBI and Carlsbad Police have refused to provide details or answer questions about the mass shooting plot.We are not aware of any ongoing threats associated with this matter in Wisconsin or California, the FBI said in a statement.The Madison Police Department also declined to comment on the plot.A hearing on the gun violence restraining order is scheduled for Jan. 3.