SEOUL, South Korea (AP) — Formally removed from office by a historic Constitutional Court ruling Friday, Park Geun-hye has lost her presidential immunity from prosecution over a corruption scandal that has sent dozens of high-profile figures to face criminal trials.

They include Park's friend of 40 years, Choi Soon-sil, Samsung's de-facto leader Lee Jae-yong, top presidential advisers, two former culture ministers and a music video director. Their charges include bribery, extortion, abuse of power and perjury.

A look at the allegations facing Park, and the key criminal defendants caught up in a scandal that has roiled South Korea for months.

PARK GEUN-HYE

Park has refused to undergo prosecutors' questioning, citing a law that provides a sitting leader with immunity from prosecution except for grave crimes like treason. But now that she's a former president, Park is stripped of that privilege and will likely face a direct investigation.

Prosecutors have accused Park of colluding with Choi to pressure 16 companies to donate a total of 77.4 billion won ($66.7 million) for the launch of two foundations controlled by Choi. They also allege that Park, along with Choi, took millions of dollars in bribes from Samsung's Lee, who is accused of seeking government support to strengthen his control over the business empire.

Park is also accused of conspiring with Choi and top officials to draw up of a blacklist of cultural figures critical of her policies to deny them state support.

Prosecutors also believe Park had one of her presidential aides convey dozens of documents with state secrets to Choi.

Park has acknowledged that she got help from Choi to edit some of her speeches. But she denies legal wrongdoing.

CHOI SOON-SIL

Choi has been arrested and charged with abuse of power, extortion and attempted fraud. If convicted on all charges, she could receive up to 15 years in prison.

Choi has acknowledged that she received some of Park's speech drafts in advance but didn't know they included sensitive information. She denies other allegations.

Choi is also 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 also faces charges that she pushed Hyundai to buy $930,450 worth of car components from a company owned by an acquaintance.

LEE JAE-YONG

The 48-year-old Samsung Electronics vice chairman faces bribery, embezzlement and three other charges punishable by at least five years in prison if he's proven guilty. A team of Samsung lawyers denied all charges against Lee during a preliminary court hearing Thursday.

Prosecutors allege that Lee and his aides used Samsung corporate funds to buy expensive horses for Choi's daughter. According to prosecutors, Samsung allegedly gave or promised 43.3 billion won ($38 million) to four entities controlled by Choi.

Prosecutors allege the money was given to obtain government backing for a contentious merger of two Samsung companies in 2015 that served as a key step in passing corporate control to Lee from his ailing father.

AHN JONG-BEOM

Park's former senior secretary for policy coordination, Ahn was allegedly involved with Choi in extorting money from 16 companies at Park's order. He is charged with extortion, abuse of power and bribery.

JUNG HO-SUNG

Jung is one of Park's close associates and worked for her since she entered politics in the late 1990s. He's been charged with passing on classified presidential documents to Choi, including information on ministerial candidates.

CHO YOON-SUN

Park's culture minister, Cho, was arrested and indicted over the blacklist allegations. She became the first incumbent Cabinet member to be arrested over the scandal, and quickly resigned. Former Culture Minister Kim Jong-deok and ex-presidential chief of staff Kim Ki-choon were also indicted over the blacklist.

CHA EUN-TAEK

A well-known music video director, Cha is on trial for allegedly using his close ties with Choi to win key culture-related projects from government agencies.