Criminologist Laurie Pieters has attended court daily and studied the evidence closely, as well as the exclusive video of Pistorius released by Sunday Night.
She claims the athlete killed his girlfriend intentionally based on Reeva's impending success and evidence she was about to leave him.
"She was on the brink of some sort of success because that very Friday her TV show was about to begin and she perhaps felt that she didn’t need him anymore," Pieters said in an interview with Ross Coulthart.
Pieters has had vast experience with domestic violence cases and says when an individual tries to leave is often when physical abuse begins.
Steenkamp appeared on South Africa's top reality TV show Tropikana Island of Treasure.
The show premiered two days after her death.
"Oscar I think was a fantastic opportunity for publicity for Reeva — but once that’s no longer necessary would you be prepared to stay in, what you feel, is an abusive relationship when you feel that you’re on the brink of break for yourself?"
The last days of Reeva’s life revealed evidence of increasing tension in the relationship, which Pieters suggests shows his jealousy and increasing attempts to control her.
Reeva sent multiple text messages to Pistorius including one that said she was "scared" of him.
"If I could have spoken to Reeva when she felt so vulnerable, when she sent the SMSs, I would have told her exactly what I tell all my clients — run."
"Don’t look back if the writing’s on the wall.
"This is not going to end well if you’re in a domestically abusive relationship and you feel threatened run get out get out and get as far away as you can."
Sunday Night previously aired interviews with forensic investigator Scott Roder who made a visual recreation of the crime with Pistorius himself.
Roder argues the Blade Runner was vulnerable without his prosthetics and believed he was protecting his girlfriend from an intruder.
"Absolutely, they physical evidence is consistent and his story remains unchanged," Roder told Sunday Night reporter Ross Coulthart.
"If you look at the evidence Oscar's clearly not guilty."
In the revealing vision, which aired last week, the 27-year-old paralympian is shown in a Nike singlet running without his prosthetic legs and pretending to hold a gun out in front of him.
It also shows how he bashed down the bathroom door and, using his sister to demonstrate, pulled Reeva from the bathroom and carried her down the stairs.
At 3.19 Pistorius called a neighbor. At 3.20 he phoned for an ambulance. At 3.21 he called Security at the compound.
Neighbours in the gated South African estate also reported hearing several sets of gunshots - the second set Roder claims were made by Pistorius breaking open the toilet door with a cricket bat.
Phuti Komo, a close friend of Reeva's, also revealed the model was feeling unsure about her relationship with the sports star.
"She felt, she felt I think, "It is a bit too much". I have lost a true friend."
Komo starred with Reeva in South Africa's top rated TV show, Tropika Island of Treasure.
Last night Pistorius broke his silence on social media exactly one year to the day since she shot and killed Reeva, quoting the bible and an Austrian psychiatrist, Viktor Frankl.