NORTH PORT, Fla. (NewsNation Now) — Brian Laundrie, a person of interest in the disappearance of Gabby Petito, is missing, a family lawyer says.

North Port Police tweeted Saturday it is searching the Carlton Reserve for Laundrie. His family reported he’s been missing since Tuesday while wearing a hiking bag with a waist strap.

North Port police spokesperson Josh Taylor said this is being investigated as a missing person case since there still is no crime for officers to investigate.

“We can’t just go just pulling people in,” Taylor said. “He certainly has the Fifth Amendment (right) not to speak.

The initial search focused on the 200 acres at the Myakkahatchee Creek Environmental Park, where Taylor said Laundrie is believed to have entered the reserve. The search is now spreading into the Carlton Reserve, which encompasses 25,000 acres.

Taylor said 50 officers from five different local agencies have joined the search for Laundrie. So far, vehicles, K9s, air units, and drones have been deployed in what is being called a grid search.

“We’re hopeful that he’s out here,” Taylor said. “Certainly, we prepare for all different possibilities, but you know, our goal is to locate him and bring him back to North Port.”

Taylor said Laundrie could be out in the nature preserve for months if he wanted, depending on his skills.

On Friday, Florida police entered the Laundrie home, where Brian, his parents and Gabby Petito live, just before 6:30 p.m. ET Friday. They left just before 9 p.m. ET.

They have brought in evidence bags and searched a car in the driveway, but nobody else came out of the house.

This week, Florida police had said they knew where Brian Laundrie was, but would not tell the public.

A small protest had been going on outside before police got there. The crowd chanted, “where is Gabby?”

It’s the latest development in the search for the missing YouTuber. Petito hasn’t been heard from since last month.

The last message Petito sent was a text to her parents on Aug. 30. Petito was last seen in an Instagram post Aug. 25 on a cross-country trip with her boyfriend, Brian Laundrie. The two left from New York, but live in North Port with Laundrie’s parents.

North Port Police Chief Todd Garrison has expressed frustration with the Laundrie’s for not cooperating with investigators.

“I truly believe he has the answers we’re looking for,” Garrison said on NewsNation Prime Thursday. “He knows where Gabby’s at, but he is protected by the fifth amendment and we’ll honor that and we’ll use all the other resources in our power to find out where Gabby’s at.”

On Sept. 11, police confirmed Petito’s car was at their house, but she was not.

“Two people went on a trip, one returned. That one that returned is not talking and he has all the information I believe that we’re looking for,” Garrison said.