Libyan leader Moammar Gadhafi is on the run, his capital all but fallen to rebels, his hometown under siege.

Now comes another difficult task for the rebels and the civilian government they are trying to install: capturing Gadhafi before the fugitive dictator is able to mount a revenge assault from hiding or inspire an insurgency that could drag on for years.

Gadhafi's wife and three of his children fled Libya to neighboring Algeria on Monday. But the Obama administration said it has no indication Gadhafi has left the country.

As U.S. forces learned in the massive, monthslong manhunt for Iraqi dictator Saddam Hussein in 2003, intelligence will be key to finding him.

Thanks to NATO and its small cadre of military advisers on the ground in Libya, the rebels will be able to draw on electronic clues known as signals intelligence, ranging from images from drones, spy planes and satellites to stolen transmissions from radio and phones — an advantage U.S. troops did not have in 2003 in Iraq, when the use of such equipment was in its infancy, and the intelligence not well shared with those on the ground.

Greed also helps. Multimillion-dollar rewards led to the capture or killing of many of what the military calls "high value targets" in Iraq, including Saddam's sons Odai and Qusai in 2003. A tipster in search of a reward revealed their whereabouts to the CIA, and the Army's Delta Force pounced, backed by the 101st Airborne Division. The combined forces ultimately killed the sons in a protracted firefight in northern Iraq.

A Libyan businessman reportedly has offered a $2 million reward for Gadhafi.

But the key to capturing Saddam turned out to be gumshoe detective work mainly by U.S. special operations forces, with information gathered largely from captured suspects. Through the interrogations, the U.S. was able to map the tribal network protecting the deposed Iraqi leader.

That effort was backed by nearly 200,000 conventional troops who helped secure a country stretching over nearly 170,000 square miles.

The Libyan rebels are being aided by small CIA teams, including former U.S. special operators on contract to the intelligence agency, as well as a small number of advisers from British and French special operations teams, according to three former U.S. officials, speaking on condition of anonymity to discuss matters of intelligence.

But that's far smaller than the U.S. effort to find Saddam. And though Gadhafi's army is dissolving in the face of the NATO-backed onslaught, the rebels have roughly 680,000 square miles to cover, an area several times greater than Iraq.

CIA officers on the ground will touch base with sources who have kept them informed throughout the battle to oust Gadhafi, one of the former U.S. officials said. But the agency does not have officers in sufficient numbers, nor the human intelligence network built on the ground yet to help the rebels conduct an effective manhunt, the official added.

One key to tracking Gadhafi will be to study what he did in the past, a U.S. official said. In 1986, when the U.S. bombed the Libyan cities of Tripoli and Benghazi, he went to the city of Sabha, in a mountainous region of southern Libya. "He was shocked and surprised," with his arm in a sling, the official said.

Two of Gadhafi's sons reportedly are leading two loyalist Libyan army units in the south as well, which could provide him support.

But Gadhafi no doubt knows that's what's expected of him.

And from watching the hunt for Saddam and, more recently, al-Qaida leader Osama bin Laden, he knows that staying off phones or other modern forms of communication and altering his "pattern of life" are key.

That's how Saddam evaded capture for so long.

The U.S.-led invasion of Iraq began March 20, 2003. Baghdad, the capital, fell on April 9. Saddam allegedly was spotted that very day in the city, before vanishing and taunting U.S. forces from hiding spots across the country.

Special operations forces that helped chase Saddam say he'd done everything right. He stayed off cell or satellite phones. He changed his behavior patterns to avoid detection. He traveled in taxis and wore traditional tribal clothing.

Most of all, he took shelter in a place that no one would have expected from a dictator who once occupied multiple palaces — and he stayed in one place, when they thought he'd move locations every night.

A special operations team finally captured Saddam in a "spider hole," dug under an outbuilding at a farm near his hometown of Tikrit, on Dec. 13, 2003.

The area where he was captured had been scoured by up to 4,000 troops.

"It was a whole brigade, multiple special operations teams, a huge reconnaissance and grass-roots intelligence effort," said retired Col. James Hickey, who oversaw the conventional forces who provided security and some key intelligence links that led to Saddam's capture.

Special operations teams worked closely with all conventional troops across Iraq, sharing information from hundreds of raids and arrests aimed at all the top officials listed in the famous deck of cards of Iraq's most wanted, according to three special operations officials, speaking on condition of anonymity to describe the still-classified operation.

Special operations and regular troops alike specifically targeted the young men from the mafia-like families who were key in Saddam's pre-invasion security apparatus.

"There were five families in Tikrit that were intimates with Saddam's family that he trusted. A lot of those members were recruited into his inner circle of security," Hickey said.

Information gained from questioning the fighting-age men captured in the Sunni Triangle helped build a database showing the hierarchy and relationships of Saddam's security structure.

Breaks came in roundabout ways.

A special operations raid in Samarra led to another raid of three sites in Baghdad. That led to the capture of a man who U.S. forces thought knew where Saddam was. His interrogation and others produced tips that led searchers to the general area where Saddam was hiding.

Hickey's 4th Infantry Division forces secured the outer perimeter, while special operations teams swept through it.

"We hit it at 8 p.m.," Hickey said.

A Delta Force assault team took the detainee to the site, according to the three special operations officials.

The detainee guided the special operations unit to a lean-to on a concrete pad, in the middle of the small farm, two of the officials said. "You want to know where Saddam is? He's there," the detainee said, pointing at a spot in front of the shed with his flex-cuffed hands.

One of the special operators picked up a shovel and scraped away the dirt, and found two rope handles attached to a piece of Styrofoam that was hiding the opening to Saddam's subterranean dugout.

Saddam was huddled inside, armed with two AK-47s and a pistol. He never moved toward the weapons. The nine-month manhunt ended without a shot fired.

But in those nine months, a Sunni insurgency inspired by Saddam took hold and plagued the country for the next five years. Remnants of it threaten security still.

The Libyan hunt for Gadhafi has just begun.