Hi there,
OH YES HAVE WE BEEN THERE
My son just recently turned 15 and thank God he hasn't had issues w/ aggression for a few yrs now,give or take a few episodes.
We too have been through a few courses of the aggresive,combative,non compliant, yada-yada-yada.... periods of time.
Christopher was in and out of the psych ward @ Childrens, meds,med changes,more meds.He was deemed "unfit for public school",the Police, and Fire Dept. having to get involved in helping me(single mom) and the "Special School" get him out of trees, other peoples cars,houses or yards, and we can't forget to mention the TRAIN. Let me elaborate on that one... the special school with a 12' fence surrounding their playground area and only 8 teenagers to oversee(10 staff members) managed to not see him scale the fence and leave the property ! My goodness, there was a "switching station" for the trains a few blocks from the school and Christopher loves trains. He got all the way there, hopped into a
moving train car and I guess was ready for the ride of his life....

The school called the police and me, but didn't go looking for him,it was a 45 minute drive for me to get there and the place was crawling with police officers and childrens services workers when I did.To make this a little shorter, someone from the train place had the common sense when they found my son on the train to call the school and ask if anyone was missing

.That is how we found him,( I'm not saying the police weren't looking,for the record,so to speak). But for pitty sake- I didn't loose him, but I got interrogated for over 2hrs before they would let me take him home.
Sorry that was so long, but I've been there.
Back to the aggression, I saw a few others who asked if you knew what set him off. Sometimes I can see that Chris is agitated before all H breaks loose,but not until the past few yrs has he been able to give me a clue as to why.
He does get worked up more in crowded/loud places, but it is usually because someone else is upset.He is very empathetic and when someone else is stressed or upset,he seems to feel it and act as if whatever is up with the other person has happened to him.
The meds: That's quite a coctail, maybe some of the meds aren't working well with each other(even if they did before),puberty and age effect these things and sometimes the good combination that worked before turnes into a huge mess for whoever is taking them. If you don't mind me saying so, it might be a good idea to talk to the doc and re-evaluate the med situation. I have had to do that a few times, take some things away,wait for them to get out of the bloodstream,see what happens and maybe try something different.
I was amazed that it turned out to be a good idea. I was scared to death, but we finally nixed everything and he started on Clonidine only-an emergengy anti-hypertensive. IT WORKED!!!!!! Chris' dx is also autism,bi-polar,and OCD. First he was started @ 0.2 mgs 3x per day, w/ another 0.1mg as a "PRN". Now we just use it as a "PRN", it also really helps with sleeping. He hasn't had an aggressive outburst, thrown the cat over the balcony, or attacked anyone in so long, I can't even remember. He had a little issue in April because his father promissed to take him out on the weekend and never showed up - JERK -. That ticked me off too, but I didn't kick a HUGE hole in the wall.
I hope this helps you, and good luck