First of all, I'm sorry that this occurred and for the injustice you suffered, that's definitely not acceptable. I'm glad to hear that you are already looking into suing the police department, that was going to be one of my first recommendations.
You should also notify the Maryland Internal Affairs, and provide them with the names of the officers and some other basic information pertaining to the date of your arrest, when you were detained, and the assault that occurred, and they will launch an official investigation into those officers. This is the phone number to the IA Department(###) ###-####
Here's a link that also has some other contact info for them that you may find useful:
The other thing I was going to suggest was bringing criminal charges agaisnt them for the assault and battery. You mentioned that you already began that process, have you spoken with the DA or someone from the prosecutor's office?
I hope that helps! Please let me know if you have any other questions. Also, please take a moment to rate me using the stars as this is the only way experts are compensated for our time here on 'just answer'. It doesn't cost you anything to rate me, and we can still continue our conversation for free after. Thanks!