Former media magnate Jimmy Lai Chee-ying, who was convicted on three charges last month under the Hong Kong Special Administrative Region’s National Security Law, began his mitigation in the Hong Kong High Court on Monday, with the proceedings expected to last four days.

The court will also review mitigation submissions from eight other defendants, including six former senior Apple Daily executives who have pleaded guilty in the same case relating to the now-defunct tabloid that Lai founded.

More than 70 people had queued up outside the courthouse by 8 am to attend the hearing. Security was tight outside the courthouse, with armed officers from the Counter Terrorism Response Unit and armored vehicles on standby.

ALSO READ: Justice was served by Lai’s conviction

The date for the sentencing will be announced following the mitigations.

The High Court found the Lai guilty of violating the HKSAR National Security Law on Dec 15 -- on two counts of conspiracy to collude with foreign forces and one of conspiracy to publish seditious materials.

The defendants included Lai and three companies -- Apple Daily, Apple Daily Printing and Apple Daily Internet – all of which were charged with conspiracy to publish seditious materials and conspiracy to collude with external forces. Lai faced a separate charge of conspiring to collude with external forces.

READ MORE: HKSAR govt slams comments on Jimmy Lai case by so-called experts

The case marks the first trial under Hong Kong National Security Law for colluding with foreign forces -- an offense that carries a maximum penalty of life imprisonment.