Brian Laundrie’s father joined Florida police in the search for his son inside the Carlton Nature Reserve on Thursday.

The increased presence by authorities comes after officials made a discovery that has become the focus of the search.

Chris Laundrie joined police to search the Myakkahatchee Creek Environmental Park, a section of the reserve that both of Brian’s parents think is the only place he can be.

North Port police say they found Brian’s car near the park a day after he disappeared. The park has been closed to the public since.

Chris Laundrie did not respond to reporters when he returned home after spending over three hours working with law enforcement to search for his son.

A lawyer representing the Laundries says the search Thursday came up short.

Water levels are receding the area, which could make it more accessible to search.

Brian Laundrie is the only person of interest in the death of Blue Point native Gabby Petito.

There is also a warrant issued for his arrest after he allegedly used a bank card not belonging to him.