A Little Technological Assistance

Agencies employ all sorts of technologies to aid manhunts, ranging from simple street cameras that can capture action on a city block to complicated facial recognition software that takes those pictures and tries to identify faces in a criminal database. (We'll see how that doesn't always work in a later section.) Things like armored trucks might also be used, especially if the suspect (like the one captured in the Boston bombings) might be carrying explosives. Many criticize police departments for purchasing the hulking machines (from about $250,000 and up) in low-threat areas (like smaller towns), but they were used during the Boston manhunt and the 2012 Newtown shooting.

As we saw in Boston, air units (helicopters) with heat sensors can also be a part of a manhunt. In addition, a forward-looking infrared device (or FLIR) detected the infrared energy from the suspect under a tarp-covered boat and allowed cops to make an arrest.

Bigger Manhunts

Now that we have an idea how law enforcement manhunts work on a mostly domestic scale, let's take a look at how gigantic, international manhunts play out. Here's one unsurprising difference: There can be a lot more collateral damage.

This is not to say that people aren't injured in smaller-scale manhunts. In the case of Christopher Dorner, who killed four people and wounded three others in 2013 in retaliation for what he saw as his wrongful dismissal from the Los Angeles Police Department, the subsequent six-day manhunt and standoff resulted in two civilian casualties. Both occurred when police mistakenly fired on a vehicle similar to Dorner's.

But when we're talking massive manhunts, the stakes are raised even higher. In the case of Osama bin Laden, President Obama ordered broader drone attacks by the CIA in Pakistan in order to both flush out enemy combatants and weaken the organizational structure that was keeping bin Laden hidden. And keep in mind that -- despite what you might see in dramas like "Zero Dark Thirty" or "Homeland" -- there were a lot of CIA officers doing very tedious work to simply piece together attacks, transactions and communications to identify al-Qaida as an organization in the first place. By teaming with the United States military forces, they were able to start targeting specific individuals.

In long-term manhunts, surveillance often helps to home in on where a suspect lies. And that surveillance is no stakeout with binoculars and doughnuts. Consider that when the government was collecting evidence that bin Laden was hiding in the Abbottabad compound where he was found, a CIA doctor conducted an "immunization drive" in the area, hoping to collect DNA samples from bin Laden children to confirm his presence in the area.

When it comes to long manhunts over a changing landscape, global criminals don't have a monopoly. Consider someone like Troy Knapp, a "mountain man" (and ex-con) who spent six years hiding from authorities in the mountains and forests of southern Utah, breaking into cabins for supplies and living off the land. Captured in 2013, authorities had used the usual tricks for a manhunt in the mountains: mobile command posts, officers on horseback and all-terrain vehicles to navigate terrain. But despite GPS and all the fancy trappings of a 21st-century police unit, Knapp was only caught when a group of suspicious hikers came upon him in the woods. Within three days, police had used helicopter units to locate the loner and surround him in the mountains. He's charged with a string of burglaries and misdemeanors.

The kind of outlaw-manhunt that takes place in the woods is not a thing of the past, obviously. But with the advent of social media and multiple technology platforms designed to keep everyone on the information grid at all times, how has a manhunt changed?