SEOUL — The jailed confidante of disgraced South Korean President Park Geun-hye begins a trial Monday that will explore a scandal that led to Park's impeachment after millions took to the streets in protest.

The trial of Choi Soon-sil, Park's friend of 40 years, is the biggest since the 2014 trial of the crew of a ferry that sank and killed more than 300, mostly teenagers.

Choi last appeared in public on October 31 when, after losing a Prada shoe in a crush of media and protesters, she told reporters at the Seoul prosecutors' office that she had "committed a sin that deserves death."

Monday's hearing at the Seoul Central District Court will review the charges against Choi, who prosecutors say manipulated state affairs and extorted businesses. It will also set the trial schedule. Choi is not required to attend this session.

The trial is open to the public. Worried about a crush of spectators, the court last week raffled admission tickets.

It's not clear how long the trial will last. Courts normally issue a verdict within six months of indictment, so she'll likely get a verdict by May if prosecutors don't bring new charges.

The charges

Choi is charged with abuse of power, extortion and attempted fraud. If convicted on all charges, she could receive up to 15 years in prison, according to court spokesman Shin Jae-hwan.

Before her arrest, Choi said she received some of Park's speeches in advance but that she didn't know if they were confidential information. She denied the other allegations.

Choi Soon-sil, a longtime friend of South Korean President Park Geun-hye, left, is escorted to get on a bus of Ministry of Justice as she leaves the Seoul Central District Court in Seoul, South Korea, on Nov. 3, 2016. AP

Prosecutors allege that Choi helped pressure 16 companies to donate a total of 77.4 billion won ($65.6 million) to create two nonprofit foundations, Mir and K-Sports.

According to the prosecution. Park first brought up the idea of launching the foundations and ordered her senior secretary for policy coordination at the time, Ahn Jong-beom, to ask companies to finance their establishment while letting Choi handle the appointment of foundation officials.

Choi allegedly used a top Chinese official's visit to Seoul to propose pressuring firms to donate quickly to Mir.

Choi has been charged with pressuring Hyundai Motors and the KT telecommunication firm to sign $6 million and $5.7 million worth of ad contracts respectively with Playground, an ad agency she ran. She was also charged with pushing Hyundai to buy $930,450 worth of car components from a company owned by an acquaintance.

Who is she?

Choi, 60, is a daughter of the late Choi Tae-min, a cult leader who served as Park's mentor. Park, 64, is the daughter of Park Chung-hee, a dictator who ruled South Korea for 18 years until his 1979 assassination.

The two women became friends in the 1970s, around the time when Park Geun-hye began serving as first lady after her mother was killed during a failed 1974 assassination attempt on Park Chung-hee. Park Geun-hye once headed a patriotic group set up by the elder Choi, while Choi Soon-sil served as head of its college unit.

Park acknowledged her ties with Choi Soon-sil after the scandal broke in October and described Choi as someone who helped her "when I had difficulties" in the past.

Choi's ex-husband served as chief of staff for Park when she was a member of parliament before becoming president in early 2013.

President Park

South Korean President Park Geun-Hye bows during an address to the nation at the presidential Blue House in Seoul on Nov. 29. Jeon Heon-kyun / Pool via EPA

President Park has immunity from prosecution for most crimes while in office. Park has acknowledged that she got help from Choi for editing speeches and unspecified "public relations" issues but has denied any other legal wrongdoing.

The country's Constitutional Court is reviewing Park's impeachment. If it rules against her, she'll be formally unseated and must undergo a direct investigation.