Short answer. Yes, this can be a valid ground for dismissal. The law allows termination for a crime or offense committed against the person of the employer or an immediate family member, and it does not limit this to acts committed on the clock or on company premises.
What the law says
Commission of a crime or offense by the employee against the person of his employer or any immediate member of his family or his duly authorized representatives
Labor Code, Article 282 — Just Causes For Dismissal. Read the full provision →
The ground the law actually names
Among the just causes an employer can invoke for dismissal is the commission of a crime or offense against the person of the employer, an immediate family member, or a duly authorized representative. The provision is written around who was harmed, not where or when the act happened. So an incident away from the workplace, and outside working hours, is not automatically excluded just because it did not occur on the job.
Who counts as covered
The wording reaches beyond the employer personally: it also covers an immediate member of the employer's family and a duly authorized representative, such as a manager or supervisor acting for the employer. An offense committed against any of these can be treated the same as one committed against the employer directly, for purposes of this particular ground. The provision does not attempt to define exactly who counts as an immediate family member, so that assessment has to be made against the specific relationship and facts involved in each situation.
Other just causes sit alongside this one
This ground for dismissal is one among several in the same provision, which also covers serious misconduct, willful disobedience of lawful orders connected to the work, gross and habitual neglect of duties, and fraud or willful breach of trust. Unlike neglect of duty, which the law qualifies as needing to be gross and habitual, this ground carries no such repetition requirement on its face — a single incident against the person it describes is what the provision names. Whether a specific incident against a family member actually amounts to a crime or offense within the meaning of this ground depends on the facts, and that assessment is separate from whatever criminal case, if any, arises from the same incident.
What this does not settle by itself
Being named as a just cause in the law does not by itself describe what process an employer must follow before dismissing someone, or what an employee can do to contest a dismissal they believe was unjustified. Those questions turn on separate rules and on the specific facts of the incident, so anyone facing this situation, on either side, should look closely at exactly what happened and who was involved before assuming how it will be treated.