A family of gangsters is somewhat like an ordinary family. It also consists of a nuclear family and an extended family, just like other ordinary families in the world. Some people are of the opinion that a family is the only social group which can accept its members as they are. If a member of the family commits a crime, the other family members tend to protect the said member, even if it means violating the existing laws.
Blood relationships certainly have in many cases impaired people's ability to think rationally. Don't be naive by disagreeing with this -- please just sleep on it! If it happens in your family, you will also feel the same way, like the family whose one member is a fugitive.
Omerta is the law of silence. It originated from the hills in Sicily, Italy. The law says the family shall not disclose any information in relation to its members which might put its members in trying circumstances. The Italian Mafia family adopts the principals of omerta in their activities. Nowadays, it seems omerta is no just longer the tradition of the Italian Mafia but also to all families around the world. It has become universal.
Indonesia has a criminal code (Wetboek van Strafrecht) which was derived from Dutch laws, i.e. Staatblad 1915-732. If the criminal code does not cover omerta, the Indonesian law makers should introduce new provisions for such situations. We have already acknowledged that the development of the society is faster than the development of the law. Therefore, we have to race against time to create a law and order atmosphere in Indonesia.