Every society has its share of violent and radical people. Therefore, we don't need a study on the cause of the Hong Kong riot. We need, instead, an unequivocal message for the Hong Kong public that violent acts and language will not be tolerated.

Grenville Cross, former director of public prosecution in Hong Kong, suggested to the secretary for justice to consider which type of courts the charges against suspected rioters would be heard in. Convictions in the High Court, District Court or the Magistrates' Court of Hong Kong could carry different maximum sentences. To achieve the necessary deterrence, a charge commensurate with the degree of potential damage caused and criminal intent should be made in an appropriate court.

Of course, meting out the necessary punishment to the guilty is not the only response Hong Kong needs. It also needs to address the concerns that worry youths, such as upward social mobility, jobs, more equitable income distribution, greater support for cultural and artistic pursuits and affordable housing. But everyone should realize there can be no quick fixes to any of these problems.

After the Mong Kok riot, there is a greater need for the authorities to monitor what is going on in Hong Kong's social media. There is an even greater need for all those concerned about Hong Kong's future to respect the law and follow standard rules and procedures. Offenders need to be brought to justice.

We hope police officers, judges and civil servants all bear this in mind.

The author is an adjunct professor and senior research fellow at the Pan Sutong Shanghai-Hong Kong Economic Research Policy Centre, Lingnan University.