(CNN) Two women accused of murdering the half-brother of North Korean leader Kim Jong Un could walk free Thursday, if a judge decides there's not enough evidence to proceed with their trial.

Kim Jong Nam died in February last year after Siti Aisyah of Indonesia and Doan Thi Huong of Vietnam allegedly wiped his face with VX nerve agent in Malaysia's Kuala Lumpur airport.

If found guilty, the women could face the death penalty.

Lawyers for Aisyah and Doan claim the two are innocent. They say the women were duped by a group of North Koreans into thinking they were participating in a prank television show and thought the liquid was harmless.

The two women have been described by friends and family as simple, well-meaning women who had expressed interest in acting jobs. Aisyah's father claimed his daughter was used and "never would have done such a thing" in an interview with CNN in October

According to authorities in Malaysia, the supposed TV producers were North Korean agents, four of whom have been charged in relation to Kim's murder but have since left the country.

Siti Aisyah (center) is escorted by Malaysian police after a court session for her trial at the Shah Alam High Court in Shah Alam, outside Kuala Lumpur on June 27.

Prosecutors say the women knew what they were doing, and had practiced the planned attack by smearing liquid on strangers in a nearby public places.

Defense lawyers say the women thought they were participating in a prank TV show, and were paid for earlier pranks as part of the job.

They also argue the investigation against their clients has been shoddy and biased, which prosecutors deny.

Speaking to CNN shortly after the incident , a friend of Aisyah's described her as friendly but naive. Aisyah had gone out and partied the night before the killing to celebrate her birthday.

"And now the person next to me will become a (celebrity)," one friend says in a video filmed that night, prompting Aisyah to laugh. It's unclear the friend knew about Aisyah's purported work in reality TV.

Life in exile

Kim, the eldest son of the late North Korean leader Kim Jong Il, had lived in self-imposed exile in the Chinese enclave of Macau for more than a decade. Though for most of his life he seemed to be the heir apparent to his father, he fell from grace in 2001 after being caught by Japanese authorities with a fake passport and cash, trying to enter the country. Kim said he was going to Disneyland.

Kim's life outside of North Korea was subdued yet lavish. However, once Kim Jong Un took the reins, experts say the young North Korean leader would have seen his older brother as a threat.

Kim Jong Nam's killing took place in February 2017, as tensions between North Korean and the international community ramped up efforts to develop nuclear warheads and the ballistic missiles to deliver them to targets as far away as the US mainland.

US President Donald Trump responded to Kim's missile tests by stepping up a campaign to diplomatically and economically isolate North Korea.

But the trial of Kim's alleged murderers has taken place against the backdrop of rapprochement between Pyongyang and Washington and a charm offensive by Kim Jong Un, who has embraced the role of a globe-trotting statesman.

Doan Thi Huong (center) is escorted by Malaysian police at the Shah Alam High Court in Shah Alam, outside Kuala Lumpur on June 27.

The prosecution completed its closing arguments in June, and Judge Azmi Ariffin is set to decide Thursday if the authorities have provided sufficient evidence to support their claims.

If he finds in their favor, the trial will continue and the defense will present their case. If he rules against the prosecution however, Aisyah and Doan could walk free, though that decision could still be appealed to a higher court.

In interviews with CNN, attorneys for both the defendants have expressed cautious optimism their clients could be freed this week.

But Malaysian legal experts said it's unlikely the case will end Thursday -- the judge will presumably want to hear what Aisyah and Doan have to say, as the two women have not yet taken the stand or been given the chance to defend themselves.