(AP) — A lawyer shot his client to death in a northern Mexico on Wednesday, then fled into an adjoining chamber and killed himself with a gunshot to the head.

Prosecutors in the northern state of Sonora initially said the two were both lawyers, and were related.

It later specified that the first victim, 27, was a nephew of the shooter, 65, as well as being his client.

The state prosecutors’ office ascribed the killing to “a family legal matter,” and said “the two apparently had an argument.” The court apparently did not have metal detectors in place.

Family courts in Mexico handle cases like custody, divorce and alimony.