Choung Won Ahn, who had been held at the Mesa Verde Detention Facility in Bakersfield since Feb. 1, died by suicide this past Sunday, according to a news release sent out by the American Civil Liberties Union (ACLU) today.

Ahn was found unresponsive in his cell, according to a news release issued by ICE.

According to the ACLU news release, Ahn was especially vulnerable to COVID-19 as he had diabetes, hypertension, and several heat-related issues. A group of attorneys made an urgent plea to release Ahn and others with serious pre-existing health problems who are at increased risk for severe COVID-19 illness.

“We are processing, and we are very emotionally upset,” said Ahn’s brother, Young Ahn in the statement. “We are angry. He did not deserve to be treated this way. He’s just a human being, but to them, he’s just a number. There are other people in the same situation. It shouldn’t be happening again.”

ICE said it notified the Department of Homeland Security’s Office of Inspector General and the South Korean consulate and requested that they notify Ahn’s next of kin.

Ahn was lawfully admitted as a permanent resident to the U.S. in 1988, according to ICE.

In 2013, he was convicted for the offense of attempted murder and was sentenced to 10 years in prison.

Ahn entered ICE custody on Feb. 21, 2020 upon his release from Solano State Prison in Vacaville.

At the time of Ahn’s death, he was in custody pending removal proceedings.