An image posted on Gabby Petito’s Instagram in February is tagged at the Fort De Soto Park in Florida, near the area where Duane "Dog the Bounty Hunter" Chapman is investigating a tip alleging Laundrie and his parents visited a campground in early September.
The image shows Laundrie smiling as he stands behind bars of a jail cell of the old fort.
The couple later posted a review of the campground at Fort De Soto Park on travel website The Dyrt, describing it as a "really nice campground, beautiful area with many hikes and easy walks, the beach, historic sites, really nice camp store and well maintained sites!"
Chapman told Fox News Monday night he received a tip that Laundrie’s parents spent the night in Fort De Soto Park with their son twice in early September from Sept. 1 to Sept. 3 and from Sept. 6 to Sept. 8.
"They were registered, went through the gate. They’re on camera. They were here," he told Fox News exclusively. "We think at least if he’s not here right now, we are sure he was caught on camera as he went in the gate — that he was here for sure."
The park is about a 75-mile drive northwest from the Laundries' home in North Port.
It’s located southwest of St. Petersburg and attracts more than 2.7 million visitors annually, according to Pinellas County’s website.
"The largest park within the Pinellas County Park System, Fort De Soto park consists of 1,136 acres made up of five interconnected islands (keys)," the website says. "These keys are home to beach plants, mangroves, wetlands, palm hammocks, hardwoods and scores of native plants. Each of these species plays a vital role in the preservation and protection of the natural environment."
The park contains more than 7 miles of waterfront and an "800-foot-long boat launching facility with eleven floating docks," the website adds.
Fort De Soto Park is located on Mullet Key. The fort built on it was completed in 1900 and is named after Spanish explorer Hernando De Soto, who visited the region during a conquest in 1539, according to the nonprofit Friends of Fort De Soto.
However, the fort never saw combat, the group adds.
"In 1941 the property was sold back to the federal government for $18,404 to be used as a gunnery and bombing range during World War II," Pinellas County says. "The property was repurchased from the United States in 1948 for $26,500."
Then in 1963, Fort De Soto Park was designated, Friends of Fort De Soto says.
Fox News’ Michael Ruiz contributed to this report.