The father of a missing Wisconsin 13-year-old said he believes his son was possibly coerced to leave his family home by another individual. James Yoblonski, 13, reportedly took his family's van and left his home in Reedsburg on 12 June, according to Sauk County deputies. The teen may have also taken his father's handgun with him. "It's not like him to do anything like this," William Yoblonski, the boy's father, told Fox News Digital. "I mean, he's never driven my vehicle on the streets or anything. He's moved my van around my shop a couple times. That was it." Security footage caught the teen leaving his home around midnight and walking across the street to where the family's van was parked, and sat inside for an hour before leaving, his father explained. Police eventually found the van by tracking his father's cellphone — which the teen also took — at the western edge of Devil's Lake State Park later that day. They found a makeshift campsite at the park they believed the boy built. Later probes into the teen's search history found he had looked up information about teens crossing state lines and boarding airplanes. Mr Yoblonski doubts that his son spent an evening at the makeshift campsite because police dogs did not pick up his scent in the area. He believes he left the area with another individual. "I think he left with somebody. I think he sat there and waited for a horn to honk and came out and got in the car with somebody," the father said. He theorises that his son met someone online or in person who may have coerced or influenced his son to leave home. James reportedly posted a video to Snapchat from his father's home shortly before his disappearance. "'I'm sorry. I don't think I'll be back for school. I don't want to hurt anybody, but I might,'" Mr Yoblonski said, paraphrasing his son's comments in the video. He believes someone else was holding the phone and recording his son in the video. Though Mr Williams has not been named as an official suspect in his son's disappearance, he knows that some members of the public are likely eyeing him as a possible culprit. He recently took and passed a polygraph test administered by the Sauk County sheriff's office, which he said he hoped would return the focus of the case to his missing son. Mr Williams has offered a $100,000 reward for information leading to his son. "I just want my son back. That's why I put up a $10,000 reward. If I could afford to go more than that … but I just don't have that kind of money. Like I said, I'm a single father," he said. Mr Williams has expressed some frustration with the lack of answers coming from the sheriff's office. Since then, the FBI has joined the search for the missing teen. Read More Father of teen missing for nearly two months speaks out after polygraph test Body pulled from river after 10-day search for missing man as three arrested for ‘murder’ Maryland sheriff calls out ‘heinous coward’ who killed mother-of-five Rachel Morin