Kim Jong Nam: The plot to murder North Korea's exiled son

Police say Kim Jong Nam died in an ambulance on February 13, after being poisoned by VX nerve agent, a substance so deadly the United Nations classifies it as a weapon of mass destruction.

He was exposed shortly after arriving at Kuala Lumpur International Airport 2 -- the terminal for budget airlines -- to catch a flight to his adopted home of Macau, a Chinese-controlled territory and gambling mecca. He had been living there for years, "more or less exiled" there, Denny Roy, a North Korea analyst at the East-West Center, told CNN in 2011.

Malaysian investigators allege Aisyah and Huong each wiped the VX on his face and then quickly washed their hands to protect themselves.

Security footage shows one of them approaching him from behind, rubbing something on his face and then running away.

Kim sought help nearby, but by the time he arrived at the airport clinic he fainted. The VX was kicking into overdrive, suffocating him. An ambulance was called, but it was too late. Kim died en route to the hospital.

The poison killed him in fewer than 20 minutes, police say.

South Korea and Malaysia publicly blame North Korea for Kim's killing. Pyongyang vehemently denies it.

Kim was born in hiding.

He was an illegitimate child in a deeply conservative country, the result of an affair between his father and a famous married actress. Kim Jong Il worried the news of his first-born son could hurt his chances of succeeding Kim Il Sung, the country's founder. So the child lived in hiding for the first few years of his life, Sung Hae Rang, Kim Jong Nam's aunt, told Time in 2003 after defecting.

Kim Jong Nam was revealed to his grandfather once Kim Jong Il's plans were solidified, according to "Exit Emperor Kim Jong Il," a book about Kim Jong Il which relies heavily on the testimony of Hwang Jang Yop, a former mentor of Kim's who defected.

He was then raised as North Korea's heir apparent, schooled around the world and eventually working for the government.

But the fall from grace came quickly.

Kim was caught at the Tokyo airport in 2001 with cash and a fake passport. He said he was trying to go to Disneyland.

Some say the excuse was a cover and believe Kim was working for Office 39, North Korea's secret operation to fill its coffers through shady dealings around the globe, "Exit Emperor Kim Jong Il" reveals.

Regardless of his reasons for visiting Japan, the scandal was nonetheless an embarrassment that revealed to the world that North Koreans traveled using fake passports.

That was end of Kim's political career. He turned to a life of self-imposed exile in Macau. Once Kim Jong Un took the reins, he would need to hide from a brother he never met and would always see him as threat, analysts say.

"Given his heritage, (Kim) Jong Nam was viewed by some elderly North Korean elites as a kind of grandson figure," Michael Madden, an expert on North Korean leadership, wrote. "This affection and relationship could not necessarily form a basis of political support domestically, but it would have been helpful had (Kim) Jong Nam ever put himself forward as a political rival to his half-brother."

Until his death, Kim lived a lavish but subdued lifestyle, fearful of a younger brother who analysts say would always see him as a threat.

Kim was killed while traveling on false documents; his passport played a role in the ensuing diplomatic row between Malaysia and North Korea.

North Korea's representatives in Malaysia publicly identified the dead man as Kim Chol, the same name as on the fake passport. Malaysian authorities used that name until they definitively confirmed Kim Jong Nam's identity, which didn't happen until about a month later.

To do that, it was necessary to conduct a DNA test and autopsy to figure out the cause of death.

Pyongyang was furious -- the man's passport said he was Kim Chol. He was their citizen, and the body should be handed back to them, they said.

North Korea's ambassador to Malaysia, Kang Chol, said his country would reject the results of what he called a "forced" autopsy. He also demanded the return of the body.

Malaysia stood its ground. Without DNA from a next of kin, the country wouldn't hand over Kim Jong Nam's body. Officials said the country was taking standard investigative procedures that are common around the globe.

Siti Aisyah was arrested on the Thursday after Kim Jong Nam's murder.

Her week began more festively: with her birthday party. On the night of February 12, the Sunday before Kim Jong Nam was killed, she gathered with a small group of friends to mark the occasion.

The scenes, which surfaced on social media, are what you'd expect: people singing "Happy Birthday," Siti blowing out candles and enjoying the company of her friends. It's what you'd expect for an intimate gathering.

What's striking is that the same woman committed murder just hours later, Malaysian authorities claim.

Investigators say Aisyah and Duong knew what they were doing in the case. The pair claim they were duped, with Aisyah's aunt telling CNN her niece thought she'd been hired to work as a comedian, pranking strangers by smearing stuff on their faces.

But authorities in South Korea say both of them were recruited by Pyongyang for the job.

Malaysian police say four North Korean men came to the country just days before the killing.

Police say Aisyah and Huong were spotted smearing people's faces at nearby malls, and believe this was "practice."

And on the day of the killing, the four men were spotted on security footage at the airport.

Police say they supplied Huong and Aisyah with the liquid to rub on Kim's face and then left the country.

Days later, the Malaysian authorities named the quartet as suspects in the case. But there's no sign that Malaysian authorities are any closer to tracking them down.

They're believed to be back in North Korea and Kuala Lumpur has asked Pyongyang to hand them over. Interpol, the international police agency, has issued red notices for them.

The North Koreans have not handed them over. For the most part, Pyongyang has insinuated that the investigation was tainted from the beginning, when South Korea was the first country to name Kim Jong Nam as the victim.

Ambassador Kang then publicly accused Malaysian officials of conspiring with "hostile forces" and expelled the Malaysian ambassador.

Eventually, each country barred the others' citizens from leaving. A small group of Malaysian diplomats and their families were prevented from leaving North Korea. And three North Koreans hid in their country's embassy in Kuala Lumpur, presumably to avoid the cops.

All the while, Aisyah and Huong sat in their cells.

The standoff lasted three weeks as the murder mystery and its spy novel plot twists captivated the world.

The nine Malaysians stuck in Pyongyang were allowed to return home. North Korea eventually got Kim's body back, which had by then been identified using DNA from his son.

Three North Koreans who were wanted for questioning but seeking refuge in the embassy were interviewed and then allowed to leave, Malaysian police said.

But the four suspects are still at large. The murder remains under investigation, which could continue for some time, police say.

Even though the geopolitical fallout surrounding Kim Jong Nam's death has subsided, for Huong and Aisyah, the story continues, with potential life-or-death consequences.