The first witness to testify in the Oscar Pistorius murder trial said Monday in a South African courtroom that she heard a woman's "blood-curdling" screams before the sound of four gunshots the night the double-amputee Olympian killed his model girlfriend Reeva Steenkamp. Michell Burger, who lives on an estate next to Pistorius' gated community said she was awoken by the screams, contradicting Pistorius' version of events, because he said he thought Steenkamp was in bed and he did not mention any woman screaming. The double-amputee Olympic athlete known as "Blade Runner," who is charged with premeditated murder for firing four fatal shots through a bathroom door at Steenkamp on Feb. 14, 2013, pleaded not guilty on Monday. Pistorius says he killed Steenkamp by mistake thinking she was a dangerous intruder in his house, but prosecutors say they have enough evidence to prove he killed his girlfriend with “direct intention." They are seeking a life sentence.