EMBED >More News Videos The father of a Modesto man accused of plotting a terror attack in San Francisco spoke with ABC30 after learning his son was involved.

Suspect in thwarted Pier 39 terrorist attack then and now. Everitt Jameson discharged from US Marine Corps for not disclosing asthma history pic.twitter.com/37JmYTZyFn — Melanie Woodrow (@MelanieWoodrow) December 23, 2017

SAN FRANCISCO (KGO) -- A father is in shock Friday after his son, a former Marine, was accused of plotting a Christmas Day terror attack targeting a San Francisco tourist hot spot.According to documents, the suspect, Everitt Aaron Jameson, offered his services as a tow truck driver to an FBI source to "support the cause."Two days ago, investigators executed a search warrant at his Modesto home -- turning up guns, ammunition, a letter he wrote including the words, "I have committed these acts," along with his will.Federal investigators say Jameson planned the attack at Pier 39 because he had been there before and knew it was a heavily crowded area. His father says he's shocked. "Something like this is unreal," he said.According to a criminal complaint, Jameson had radical jihadi beliefs and had social media posts that supported terrorism.He told an FBI undercover employee that he had interest in planning and undertaking a violent attack in San Francisco in support of ISIS."He said he could do it the week of December 18 to the 25 and said Christmas was the perfect day," the complaint documented.He also offered an FBI source his services as a truck driver to support the cause. Jameson has worked at Anderson's Towing since August 21."This event brings this terror stuff way too close to home," said manager Duane Thompson. He added that the towing company is cooperating with the FBI in every way possible. His reaction was that Jameson may have intended to use the trucks here as part of his planned terror attack.According to the complaint, Jameson was discharged from the US Marine Corps for fraudulent enlistment because he hadn't disclosed an asthma history.His weapon of choice was an assault rifle. He explained he was trained in both the M-16 and AK-4.After an FBI employee accidentally called Jameson from a 202 area code and hung up, the next time an undercover agent spoke to Jameson he said he had "reconsidered."Still, when law enforcement officials executed a search warrant this week, they seized a letter with the words, "You have all brought this upon yourselves."They also seized Jameson's will, firearms, and ammunition.In his interview, Jameson's father also suggested he may have changed after his children were adopted. His estranged wife has also had trouble with the law. Jameson appeared in court this afternoon. If convicted, he faces a maximum 20 years in prison and $250,000 fine.