NORTHRIDGE (CBSLA.com)   —  The father of a 26-year-old man who reportedly made threats against Pierce College on social media, said his son was only joking.

It’s a story that is Only On 9.

READ MORE: One Crew Member Killed, Second Wounded After Alec Baldwin Discharges Prop Gun On Movie Set In New Mexico

Officials said they found weapons and ammunition at the home of Sergio Castanon Jr.

The school is open again Thursday evening. Earlier in the day, because of the threat the school was shut as a precaution.

Castanon Jr. is a former student at the Woodland Hills campus.

The suspect’s father — Sergio Sr. — spoke to KCAL9’s Erica Nochlin.

Castanon’s father told Nochlin he was surprised by the threat but he insisted it was a joke and a mistake.

Officials took the threat very seriously.

“There’s nothing to worry [about],” the man’s father said, “I know my son.”

“When things go wrong, you might say something that you will regret later on,” said the father.

Officials said they confiscated an assault rifle, a handgun, illegal high-capacity magazines and other rounds of ammo.

READ MORE: Teen Gets Up To 9 Months In Juvenile Camp For West LA Lamborghini Crash Which Killed Monique Munoz

Two of Castanon’s Facebook friends apparently contacted authorities and Thursday morning the decision was made to evacuate the campus.

Sergio Sr. told Nochlin his son purchased the weapons two years ago and uses them at the firing range only.

His Facebook page, Nochlin reported, is filled with gun references and images.

Castanon’s bio reads, in part, it’s sometimes “necessary to act outside the law, to pursue natural justice, not vengeance. Punishment.”

The father insisted his son was just talking tough and that he’d never act out on an actual threat.

“I can’t describe it, I don’t want to see my son in jail,” Sergio Sr. said.

Castanon Jr. posted his $50,000 bail and is now free.

The Sheriff’s Office doesn’t believe he poses much of a threat without his arsenal.

RELATED STORY:

MORE NEWS: Several Hurt In Wreck On 101 Freeway In Woodland Hills

Arrest Made After Pierce College Evacuated Over Social Media Threat