NORTON SHORES, Mich. (WZZM) -- The sex offender Norton Shores Police questioned Wednesday night in the Jessica Heeringa case voluntarily returned to police Thursday for additional questioning.

He was person of interest number 25 in her alleged abduction, according to Norton Shores Police Chief Daniel Shaw.

WZZM 13 was the only crew on the scene in Muskegon Heights to witness the FBI and multiple other police crews question the man in the silver minivan. But Chief Shaw says this scenario has played out almost 25 times, just not in the public eye.

"I would call this more routine," said Shaw.

So how does the routine work once police have questioned their person of interest? Shaw says it's a team effort. "The investigator or person working the case provides information to the whole team."

For the Heeringa case, that team includes 30 to 40 people at any set time. And in this investigation, the information centers on that one big piece of evidence.

"Our lead investigators will say, 'What do you think, is this a good guy to look at, or is this a good van to look at?'" said Shaw.
"See if he has access to a silver van. Find out his whereabouts on Friday evening."

If the team doesn't find any solid clues or connections, it comes down to decision time.

"Then they would give a presentation, if you will, to the whole group and decide 'No, we don't need to look at this person any longer.'"

In a case like Heeringa's, Shaw says it's important to have a huge team of eyes to make sure no stone goes left unturned. "More minds looking at one situation the better, because one person might see something a little bit differently than another," he said.

Shaw says that person is then free to leave the state if he or she wants to. But if another tip comes in, and Shaw says Facebook has been helping with that, the police may pursue the person again.

He says investigators are still only searching the Muskegon/Norton Shores area because they don't have any leads that make them believe is Heeringa is elsewhere.

Shaw says police have received multiple offers from volunteer groups who are willing to ground search with K9s. Police used search dogs the first two days Heeringa disappeared.

He says they are exploring that option, but says it's tricky because all the land in the area is private, except for Hoffmaster State Park and a few areas near the lakeshore. Shaw says they need permission from multiple people and businesses to search on their property.