RBBM
I don't think we can in all honesty. My ex wrote me love letters, cried on his knees begging me to forgive him, and told me I was beautiful everyday. He also told me I was stupid, set our house on fire, and disabled my car to prevent me from leaving while he proceeded to smash our furniture. To outsiders, he appeared to adore me. Very often, emotional abusers are charming enough that friends and family will be none the wiser to the abuse - until and unless it escalates. It's part of the reason why victims don't necessarily recognise abuse. Everybody else keeps telling you how great your significant other is. That Myers and Steenkamp both interceded on Reeva's behalf is telling to me.
(Not to compare my relationship to Reeva's but to highlight that abusers keep their victims in the relationship by appearing remorseful, loving, complimentary and apologetic. If they were gits all the time, no one would stay. It's a constant see-saw. Over time though, an erosion of confidence occurs and the victim usually blames him/herself for the abusive behaviors instead of calling out the abuser for their behavior.)
MOO