MINNEAPOLIS (WCCO) – Police have searched fields, an airport and now near a casino without any sign of Lyle “Ty” Hoffman. He’s been on the run for more than three weeks, wanted for murder.

As searches continue, we had viewers ask, just how do investigators decide which tips to follow up on and who to talk to?

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How exactly do manhunts work?

WCCO took that Good Question to two officers who’ve called the shots behind the scenes before.

Like a lot of us, Don Davis is anxious for the search for Hoffman to be over.

After spending half of his 35-year career as a police chief, Davis has seen manhunts often end close to home.

“You get this vision sometime that they’re first class bound for another country often that’s not the case,” Davis said.

Davis calls murder suspects desperate with limited means for escape.

“Tips many times lead to an arrest,” Davis said.

He says investigators have to rely on other agencies to assist in following-up on all the tips they usually get.

Davis remembers a case from 20 years ago when a man killed a woman and stole her car in Brooklyn Park and threw her child’s car seat out.

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“You can’t believe how many infant seats are lying between Lake Street and the Iowa border,” Davis said.

Ultimately, police arrested Rico Barlow a week and a half later, hiding out in an apartment a few miles away.

Hennepin County Sheriff Rich Stanek says technology has helped to change manhunts since then.

“Social media is one of the first places we go,” Stanek said.

When Boston Police released photos of the men they believed were behind the marathon attacks crisis communication went into overdrive.

Both were captured, or killed, by the next day.

The sheriff said it’s the work that we don’t see that dictates what we do see on TV.

The search for a man they consider capable of deadly violence continues.

“You want to stop that before anyone else gets hurt,” Stanek said.

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Police consider 24 to 48 hours after a crime to be the most critical.  That’s why police immediately interview family, friends and colleagues.

Liz Collin