Assault & Battery: An Adult Assaulted My 17 Year Old

My question involves criminal law for the state of: Indiana
Hi,
My son works at a fast food place with a 19 year old girl. Him and this girl have exchnaged friendly text messages over the last couple of weeks. this past Monday,he sent her a msg asking if she was still sick(she called in sick on sunday)because he needed to know if he had to close,cover her hours etc. I must mention that in the course of the last couple weeks of "friendly" text msgs, she sent him pics of her in her new bra,etc. Monday night, when he got off work,he had stopped in the parking lot to air up his tire w a portable air pump. This girl and her boyfriend pulled up and blocked my son in and the boyfriend,who is 21, got out,went up to my son,ripped his glasses off his face,(my son is legally blind without his glasses)proceeded to yell,scream etc t him to leave his girlfriend alone.he then punched him in the stomach,pushed him in the truck causing him to bash his head, then threw his glasses across the parking lot. While, the girl who was sendng him the msgs sat in the vehicke and watched!! and said and done nothing! when he came home and told me, i called her and asked for this guys full name,address and phone number.the conversation got ugly.she said "i will file sexual harassment charges agianst your son to get him fired, i will say he touched my pussy", i said "did he touch you"? she said "no, but i will say he did to keep me out of trouble". (which i have no idea what that meant). i told my son to call a mgr that was on duty and let her know what had happened. well, the little twit called the mgr just 5 mins before my son did.we made a police report.First I want to know what happens from here. It is my understanding that since my son didn't have marks thats why they didn't arrest this guy right then, and that my son came home instead of calling from the location of the attack. All this week i have sat in meetings with him and different levels of mgmnt.In the last 5 minutes of the last meeting it occured to me to ask my son, "have you seen any paper or any kind of document that states what exactly your accused of? that except for mine and her conversation about him touching her p*ssy, you have no idea what exactly she is accusing you of correct"? he said no, he just knows sexual harassment. I then asked the mngr, "when exactly is she ssaying this touching occured"? the mgr said "she is saying it's been happening but he touched her at work sunday", thats when i said "this is bullshit, neither of them was at work sunday",(up until this point, i had been very professional, kind and understanding). Last night, she sent him a msg that said "i am sorry i didn't stick up for you during the whole Brad thing".(thats her 21 yr old boyfiend that assaulted my son), i told him, DO NOT TEXT BACK! he has emailed all the text msgs that have been sent back and forth prior to this to mngmnt. (his reply on the all the papers hes been handed as far as explanation has been "since it is such a small area in the fast food place they work at,when he has to squeeze behind another employee he puts his hands on their waist to let them know he is behind them,steady them etc,just like i have done in some situations,except maybe not waist,but perhaps shoulders). the employer is doing nothing about the assault since it happened after hours and outside of the gate,they are just handling the sexual harassment. my question is this. when will they arrest this 21 yr old? the police officer said a detective will contact us, what happens from here? they have this guys address. I have never felt this kind of rage in the pit of my stomach before. my son is 6ft 230 lbs, this guy is 6 ft 350 lbs. the thought of my son feeling around the lot for his glasses, puts me in such a rage i can't stand it. I have been upset in the past if kids have made fun of him when he was younger, but this is something in my gut i have never experienced before. It is my God-given right to protect my son at any cost. i am sure he will be cleared of any wrong doing at work. I just would like to know when is the police going to do something and what type of punishment he will receive. Any help in this would be appreciated greatly!!!
Thank you
(a mom grizzley bear that wears eyeliner)

sorry, just wanted to make sure it posted cuz i typed all that and realized i wasn't signed in