The captain of a South Korean ferry that sank in April apologized in a Gwangju District Court for actions that led to the deaths of more than 300 passengers, many of whom were high school students on a class trip. Capt.  Lee Joon-soek told the courtroom Wednesday he was “confused” at the time of the accident, according to news reports.

“I committed a grave sin. I’m sorry,” Lee said, according to the Associated Press. “I know I cannot get out of prison, but I must not let my children and grandchildren live being called family members of a murder.”

Lee was one of four ferry crew members indicted on negligent homicide charges for failing to protect the Sewol’s passengers. He claims that he ordered the ship to be abandoned, but that passengers didn't heed his command. The ferry’s 15 crew members were among the first to flee the sinking ship.

Prosecutors allege that this claim contradicts what Lee told police after the incident. Survivors have said they were told over the ferry’s loudspeaker to remain on the ship.

"What the captain and part of the crew did is unfathomable from the viewpoint of common sense, unforgivable, murderous behavior,” South Korean President Park Geun-hye said at the time, according to NBC News.

Lee wasn't at the ferry’s helm when a sharp turn caused it to capsize. Authorities have blamed the accident on a combination of an inexperienced helmsman, illegal modifications to the ferry and too much cargo in the ship's hold, BBC News notes.

If convicted, Lee could face the death penalty. The court is expected to reach a verdict in November.