Thursday's lull in the manhunt for accused murderer Ty Hoffman underlined the difficulties that law enforcement agencies face when looking for a dangerous fugitive who's determined not to be found.

In the art and science of the manhunt, time is everything, law enforcement officials said Thursday.

"Every hour that passes that you don't capture somebody, you are losing crucial time," said Ramsey County Undersheriff Jack Serier.

Serier, who has spent 24 years in police work, said the general public often loses interest when days turn into weeks.

The first 24 to 48 hours after a crime has been committed are the most critical for following fresh leads, said Hennepin County Sheriff Rich Stanek. It's also when the most hands are on deck.

The hunt for the 44-year-old Hoffman, who has been on the run since Aug. 11 after allegedly shooting and killing onetime business and romantic partner Kelly Phillips, 48, has unfolded in several stages. Just after the fatal shooting at an Arden Hills gas station, investigators worked intensely to identify and then find the suspect. Then, for several weeks, the search for Hoffman, while ongoing, was not particularly intense, at least not publicly.

But on Sunday, an armed bank robbery in Blaine Sunday reignited a dramatic public search involving dozens of officers and heavy equipment. The man who hit up the bank, making off with an undisclosed amount of money planted with a red-dye bomb, closely resembled Hoffman in surveillance photos. Suddenly, Hoffman was back in the public eye, especially as law enforcement warned repeatedly that he is armed and dangerous.

"And so the manhunt begins," Stanek said of what happened next.

From Sunday through Wednesday, officers combed through buildings and brush from Blaine to the Mystic Lake Casino area in the south metro, tracking reports that Hoffman had been spotted in those areas.

Despite the TV images of heavily armed officers and armored vehicles in the Hoffman chase, most of the time a manhunt starts behind the scenes, away from the public eye, Stanek said. Much of the work involves talking to witnesses and colleagues and visiting places where the subject of the search lived, worked and hung out.

Even Thursday, with no publicized sightings or searches for Hoffman, the investigation was continuing, experts say.

"Usually a manhunt looks like my campaign office," Stanek said. "Lots of papers on the walls. There's a working board, where I'm putting all the information and making sense of it all."

Old-school ways of finding a suspect remain relevant, but a modern manhunt also can involve analysts sitting down with computers and using databases to string tips together, the sheriff said.

Another important step involves looking at a suspect's safety net: Who did the suspect live with? Who are his friends?

Glenn Negen, a retired officer from the Willmar Police Department, said investigators know that most people are creatures of habit.

"Look at what's the norm for them," said Negen, who spent 34 years in police work. "People tend to go to family when they get in a stressful situation."

Learning about an individual suspect's behavior is equally crucial, Serier said: Where did the suspect work? What stores did she frequent?

When a search becomes intensely public, officials turn to the public for help.

Citizen sightings 'priceless'

In every manhunt Serier has been a part of or seen, the public "plays a key role in finding the people," he said.

"Regardless of all the camera systems and all the technology available, it pales in comparison to a person walking in a mall or down a sidewalk and calling us," Serier said. "The eyes and ears of the public are absolutely priceless for us."

Most tips from the general public can prove useful. But there are many that are false leads, too. Sometimes people call in tips because they want the notoriety, Negen said. And sometimes people's sightings are simply wishful thinking, Serier added.

Investigators can weed bad tips out by looking at the credibility of the source who spotted the suspect, as well as asking: Does it make sense for the suspect to be at the reported location? Does he or she have family or friends in that area?

Throughout the process, those behind the scenes use search warrants to track the suspect's digital and physical footprint.

"Think of things you use every day and what would be traceable," Serier said. "Those items are big for us."

The decision to pull other agencies in a manhunt and the time it takes to do so differ in each case, said Lt. Eric Roeske, spokesman for the Minnesota State Patrol. The patrol, whose officers work statewide, is called on when agencies need extra support, he said. In the hunt for Hoffman, the patrol enlisted its helicopters to help in Blaine and later, in Prior Lake.

Citizens' sightings of Hoffman have been one of the driving forces in the search for him, and on Thursday, authorities continued to urge anyone spotting him to immediately call 911.

"It's pretty hard to become anonymous," Stanek said. "Either you are really good at it, or you are dead."

Karen Zamora • 612-673-4647