Finally, on October 7, 2019, Lu "admitted to investigators that he created the code described."

[...] said Lu's attorney, Ian Friedman, adding that they intended to appeal. "Davis and his supporters believe in his innocence and this matter will be reviewed at the appellate level."

Never admit culpability. There's always the chance some unknown nation-state-level hacker or other disgruntled employee is doing active sabotage and using the name and credentials of a recently laid off employee to do it. That's what an intelligent hacker would do, not foolishly leave their own name and credentials attached all over the incriminating data.

Cops always want confessions because proving a crime happened is much harder. Especially with highly tamperable computers which are so difficult to explain to juries.