Following my previous post, I am concern that both two theories: “Differential Association” and “Techniques of Neutralization”, were first introduced over 50 years ago, are they still applicable to the current situation?

My pleasure.

Thank you very much for the explanation.

These theories were indeed introduced a long time ago, they continue to receive recognition in present-day literature. For example, D. A. Andrews and Bonta (2010) designated criminal attitudes to be one of the “big four” covariates of criminality and assign them a primary role in their general personality and cognitive social learning (GPCSL) theory of criminal conduct. More specifically, situated in conjunction with an antisocial peer network, antisocial personality pattern, and history of antisocial behavior, antisocial attitudes feature prominently in the origin and maintenance of criminal behavior. Among these approaches is a common theoretical thread woven throughout a tapestry of attitude–criminal behavior relationships; that is attitudes matter. They are relatively stable (yet changeable) affect–cognition–behavior conglomerates with causative relevance in the origin and maintenance of criminal behavior, although the mechanisms by which attitudes form and are made manifest in behavior may vary with specific models of attitude change.

You could find more information below:
Andrews, D. A., & Bonta, J. (2010). The psychology of criminal conduct (5th ed.). New Providence, NJ: LexisNexis.