Please understand that there is a very good reason why the practice of law requires graduation from an accredited law school and a passing score on a formal examination. Doing online research is all well and good. But it is not the final word. There are a combination of factors that impact a defendant's sentence. I respectfully suggest that your brother is better served by taking legal advice from his public defender who is no doubt more familiar than you with the Sentencing Guidelines, mitigating factors in your brother's case, and range of sentences imposed by judges in Lehigh County for this offense.
Please understand that there are many factors that come into play in estimating a likely sentence for a particular conviction. Judges get paid lots of money to determine appropriate sentences for convicted offenders, and the PA Sentencing Guidelines are simply ONE factor bearing on sentence. What I am about to say with respect to the guidelines range in his situation is entirely based upon the information that you have provided that he has a Prior Record Score of 1 and that he is charged with a Felony 3 Escape charge for leaving work-release. The specific charge, if you correctly identified it, is §5121(d)(1), which is graded as a Felony 3. The guidelines would provide on these facts for a standard range sentence of between 1 to 12 months for the minimum part of the sentence. In PA sentences are composed of a minimum to a maximum, the guidelines are addressed to only the minimum component of a sentence. Furthermore PA sentencing law requires that the maximum be at least twice the minimum. What that means is that if the sentencing judge decided to sentence within the guideline standard range his lowest possible sentence would be a sentence of 1-2 months. As mentioned, the maximum must be at least twice the minimum, but it can be greater--all the way up to the maximum time the particular charge permits. For a Felony 3 that statutory max is seven (7) years. Accordingly the judge COULD, although I've never seen anything like it, sentence him to the minimum under the guideline and max out the maximum. So that would translate to 1 month to 7 years. If the judge chose to use to top end of the standard range (12 months), his sentence would have to be at least 1 to 2 years, it could be as high as 1 to 7 years. There are obviously many many variations allowable, that's why they get paid to figure it out. The fact he turned himself in has NOTHING to do with the application of the guidelines, but it certainly speaks in his favor to the judge who will sentence him. I see no reason to doubt the information from the PD. They know the local system and tendencies of their judges.