Nearly 21 years after Nguyet “Anna” Nguyen’s disappearance, King County Sheriff‘s detectives arrested an ex-boyfriend in connection with her murder. He was also charged Friday in King County Superior Court with second-degree murder and held on $2 million bail.

On Nov. 9, 1998, 28-year-old Nguyen told her mother and 11-year-old daughter she was leaving their Seattle home to visit her fiance. That was the last time anyone heard from her, King County Sheriff’s officials said in an emailed news release.

The initial investigation into her disappearance began the next day, after she was reported missing by her family. The day she was reported missing, she had plans to fly to Reno, Nevada to marry her fiance.

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On Nov. 11, 1998, her vehicle was found in a Tukwila casino parking lot. An ex-boyfriend of hers, Phan Seng, who was 42 years old at the time, was interviewed during the investigation. Though he denied any involvement, he kept changing the story of where he was at the time Nguyen vanished.

“Detectives suspected foul play early on in the investigation,” the release stated.

Nguyen’s body was never found, but a death certificate was issued for her in 2015.

Then, this year, detectives with the King County Sheriff’s Office re-examined the case and its evidence. New facts were gathered this time around that allowed investigators to make an arrest.

Detectives visited Seng’s residence on Oct. 23, 2019 and let him know they were still investigating Nguyen’s disappearance. He immediately asked if he was going to be arrested, charging documents said. He also told detectives that he still hadn’t heard from Nguyen and that he was not at the casino the night of Nov. 9, 1998.

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Surveillance video from 1998, recently reviewed again by detectives, shows Seng arriving at the casino from the direction where Nguyen’s car was found, and leaving about two minutes later in a different direction. No footage shows Nguyen arriving at the casino.

Further surveillance footage and records show Seng using multiple ATMs to try to withdraw cash from Nguyen’s accounts, charging documents say. He was also found with pieces of identification for Nguyen and her daughter, which were normally kept in Nguyen’s purse.

Seng’s brother eventually told detectives that Seng had asked him to tell police he was with him working on Nov. 9, but they were not working, documents alleged. The brother told detectives he saw Seng at 9 p.m. on Nov. 9, 1998 and then didn’t see him again until Nov. 11, 1998.

Additionally, charging documents showed Seng has prior felony and misdemeanor convictions involving Nguyen. The charges of assault, interfering with domestic violence reporting and malicious mischief resulted from an encounter with Nguyen on Sept. 25, 1998 where he strangled her, broke her framed photographs and threw her phone after she told him she wanted to end their relationship.

Seng was booked Friday into the King County Jail on investigation of murder.

This is the fourth cold case arrest made by King County Sheriff’s Office major crimes detectives this year.