A Wisconsin college student and her boyfriend believe they gave a ride to a hitchhiker who turned out to be Brian Laundrie.Miranda Baker goes to UW-Oshkosh.She spoke with ABC News about her encounter with a man who she new believes was Laundrie while at Grand Teton National Park."I saw a video and saw his face, and, I'm like, 'Oh my gosh, that's the man who I gave a ride. I immediately called the police," Baker said.She is now a crucial witness in a national manhunt for Laundrie. He's a "person of interest" in the disappearance of his girlfriend Gabby Petito. Police found what they presume are Petito's remains on Sunday."My boyfriend and I were coming into the Tetons from Yellowstone," Baker said. She graduated from Kimberly High School.Baker and her boyfriend traveled out west last month.The hitchhiker to whom they gave a ride offered them $200 for a lift on Aug. 29. "When he first came up to us, he introduced himself, you know, 'Hi, my name is Brian,' you know, 'I'm just looking for a ride,'" Baker said.She posted several videos about the interaction with Laundrie on her TikTok page with detailed descriptions and maps of where they gave him a ride."He had told my boyfriend and I (that) he — him and his fiance, he never referred to her by name — were doing a cross country road trip and that she was back at their van at a disbursed campsite working on their social media," Baker said. "He referred to them as digital nomads."She said Laundrie was in her Jeep for 23 minutes before he got out.Three days later, Laundrie returned to Florida without his girlfriend. Petito's parents reported her missing on Sept. 11.Now, he's disappeared."It was a little strange. I've never picked up a hitchhiker. So, it was definitely strange. But he seemed nice. He was our age. Nothing seemed off about him," Baker said.She added that, looking back, it's strange Laundrie was traveling separate from Petito. Baker said she has been cooperating with the FBI.