Poor girl upstairs.

So me and my husband lives in a apartment. About 3 weeks ago, a couple on their late 20's just moved in on the unit upstairs. Since then I can always hear them fighting, plus heavy foot steps as if their physically hurting each other. I can always hear it almost every night. Sometimes I wake up to it cause I can hear the footsteps and throwing of things. My husband sleeps really early cause he feels tired from work and he's a heavy sleeper so it's really hard to wake him up. But last night, while I was cooking our dinner and my husband is just sitting by the kitchen counter. Omg, we heard really heavy foot steps as if someone is running and the other one is chasing. Then we heard noises as if someone is destroying something with a hammer. We also heard slamming doors and the usual throwing of things. We could hear them yelling at each other, but we couldn't understand what they're saying to eavesdrop. My husband asked me if he should go upstairs and tell them to stop cause it was really a lot of noise for us. Then few minutes later, the girl started screaming really loud. She kept screaming, "Ouch!!! Let go! Let go of me! Ouch!!!" then another session of slamming and tunning noises happened. 
I feel like I want to help her and could've called the cops last night. But I just told my husband that we should stay out of it. Cause it happens every night. But I know for a fact that she's the one who keeps coming back to him. Cause sometimes my husband and I saw the guy couple of times going home early, alone. And the girl would be there by 6PM. One time we ran in to each other when me and my husband was on our way to the parking lot. I saw her for the first time, and she can't even look up. As if she's trying to hide a bruise on her face. Poor girl. 🙁 And also one time, since our cars is parked next to each other I saw her checking out the receipts and other papers on the guy's car. I can tell that she's on a abusive relationship obviously. But I also know for a fact that if we called the cops and tried to help her, she would just cover for his ass and pretend as if they weren't fighting and she's ok. Plus the guy looks like some sort of drug dealer or criminal. And his car driver's door has no handle or knob... As if it was stolen. I find it really disrespectful too sometimes in our side cause they don't act as if someone is living downstairs, like they don't mind if they're disturbing someone. Also this morning, my husband and I woke up and found a pile of the guy's clothes on our pathway. Guess she threw those from the valcony although she knows that she will be dropping it on our front. It really seems like both of them are crazy. But I'm not sure of how my and husband and I should handle it.