Well, you don't mention what your son's original charge was. But, while you may consider the actions your son took to violate his probation/parole as "minor," (and probation and parole are two very different things. You really need to specify which is the case) it appears from the sentence he received that the original charge(s) were not minor at all. I don't buy that your son received this sentence "without a trial." If no actual trial occurred, it was because your son pled guilty, likely in a plea agreement regarding sentencing. That is quite different than the implication of your "without a trial" statement...as if NM was a dictatorial 3rd world county where people are imprisoned without due process.

You ask about sentencing guidelines. That is impossible to answer without knowing what charge(s) your son was originally convicted of. There are no sentencing guidelines for probation/parole violations, per se. Sentencing is based on the offenses involved in the original conviction.

You also state that there were no "aggravating circumstances." I find that a bit hard to believe. Although any probation violation carries the possibility of full imposition of the original sentence (which is what your post suggests happened), it rarely happens for relatively minor first violations. Unless adherence to a curfew was somehow essential to the state's interest in preventing your son from reoffending his original crime(s), I strongly suspect that this was not your son's first probation violation...in this situation, prior violations would constitute "aggravating circumstances."