You need a DWI attorney to properly evaluate the evidence against you in this case and whether or not this was a legal arrest and stop.
Visit my website or give me a call and I can present you several options that may meet your budget as I regularly handle Frisco DWIs.
Collin county where Frisco is located has a blanket policy of not reducing DWIs so handling it yourself probably won't get you a deal you would want.
In Criminal trial the court is allowed but does not have to give or instruct the jury with instructions that include lesser included offense. This depends off course on the evidence introduced during the trial and the law argued to that judge as it applies to the facts in the case.
However in capital crimes, my understanding is that the United States Supreme Court has held that the court SHALL instruct the jury that they may find the defendant guilty of a lesser included offenses .See Beck...
Home interlock is a standard condition of bond on a case like this. One major fact missing from your question is the BAC or blood alcohol content as the limit is a .08 in Texas. However, the DA will argue a synergistic effect with the sleeping pill which caused your friend to lose the normal use of mental and or physical faculties which are 2 other ways to prove intoxication in Texas.
I would suggest to have your friend meet with several DWI lawyers and pick the best one for his budget and...
Considering that CPS is involved you need to take this seriously and its now time to hire an attorney. Additionally, what you post on this website is not private so do NOT make any more admissions regarding the facts of your case -- as it can be used against you.