PRETORIA, South Africa (AP) — Oscar Pistorius was testifying for a second day at his murder trial Tuesday, answering questions from his defense lawyer.

Pistorius is expected to speak about the night he shot girlfriend Reeva Steenkamp and will also be cross-examined by the prosecution.

The double-amputee Olympic runner was the second witness called by the defense Monday, when he made a tearful apology to Steenkamp’s family. He said he was now on medication and suffered from panic attacks, and had a long-held fear of crime, which he says contributed to him firing through a toilet door on Valentine’s Day last year thinking his girlfriend was a nighttime intruder.

Prosecutors say that Pistorius is lying and killed Steenkamp intentionally after an argument and charged the world-famous athlete with premeditated murder.