Here's A Re-Enactment Of How Oscar Pistorius May Have Killed His Girlfriend

When Oscar Pistorius goes to trial in June, the question won't be if he shot his girlfriend Reeva Steenkamp, it will be how, and why. Pistorius' defense claims that the runner mistook Steenkamp as a burglar and shot her through the bathroom door in defense.

ABC's 20/20 reconstructed a model of Pistorius' bedroom to show viewers what could have happened that night.

ABC's Dan Abrams walks viewers through the replica with Amy Robach. Abrams first points out that the doors in Pistorius' room were open to the outside and that neighbors heard the couple fighting:

Screengrab from ABCNews

Prosecutors believe Steenkamp then flees to the bathroom which is down a hallway. Pistorius then puts on his prosthetics which are at the foot of the bed:

Screengrab from ABCNews

And then comes around to the left side of the bed, and grabs his gun from underneath, allegedly not realizing Steenkamp was not in the bed at the time:

Screengrab from ABCNews

Then Pistorius walks down the hallway to the bathroom, allegedly following Steenkamp:

Screengrab from ABCNews

Pistorius then fired four shots through the bathroom door, three hit Steenkamp in the hip, elbow, and head:

Screengrab from ABCNews

Abrams and Robach note that in the small bathroom, Steenkamp really had nowhere to hide:

Screengrab from ABCNews

There's also the bloody cricket bat that was found. Steenkamp's autopsy has not been released, so whether or not Pistorius assaulted her with the bat, or as the defense says, used the bat to knock down the door and help Steenkamp, is unknown:

Screengrab from ABCNews

One piece of evidence which may help the prosecutor is the two cell phones that were left by the bathroom mat, one of which was splattered with blood. The prosecutors say that it doesn't make sense that Steenkamp took the two cell phones with her just to go to the bathroom in the middle of the night, and that they may indicate there was an argument:

Screengrab from ABCNews

Joey Jackson, a defense attorney, then walked Robach through the replica with what Pistorius' defense says happened. The biggest difference: the defense says Oscar heard a noise after the two had already fallen asleep, grabbed his gun, walked to the bathroom, and saw an open window. The defense also says he was not wearing his prosthetic legs. There was construction going on at Pistorius' house and the runner remembered that there were ladders leading to his window, making him think someone was able to break in:

Screengrab from ABCNews

The defense says Pistorius then saw the locked door, and assumed an intruder was in the bathroom and fired shots.

You can watch the entire 20/20 segment at ABCNews.com >