02/19/2013 at 10:45 AM EST
Charges against Oscar Pistorius
have been upgraded to premeditated murder, after the judge in Pretoria, South Africa, said during Tuesday's bail hearing that he could not rule out the possibility that the "Blade Runner" track star
planned the shooting death of girlfriend Reeva Steenkamp, reports CNN
Magistrate Desmond Nair said he would consider downgrading the charge at a later date. Wearing a blue shirt and gray suit, and sometimes clenching his jaw, Pistorius also openly wept in the packed courtroom
as prosecutors provided details of their accusations.
Prosecutors said Pistorius, 26, opened fire on Steenkamp, 29, four times through a locked bathroom door of his home in a gated community last Thursday after attaching his prosthetic legs and walking more than 20 feet from a bedroom.
Prosecutor Gerrie Nel said Steenkamp, a model who only recently had made her debut in a reality TV show
, had been in a room less than 20 square feet when the shots were fired, reports The New York Times
"She could not go anywhere," said Nel. "It must have been horrific."
A lawyer for Pistorius, Barry Roux, said the defense would "submit that this is not a murder
," citing a lack of evidence or motive
"I fail to understand how I could be charged with murder, let alone premeditated," Pistorius said in an affidavit read in court by Roux and obtained by PEOPLE, "I had no intention to kill my girlfriend. ... We were deeply in love and I could not be happier. I know she felt the same way."
He also said, "I believed someone had entered my house. I was too scared to switch a light on. I grabbed my 9mm pistol from underneath my bed."
After the gun blasts, Pistorius said in his affidavit, "I returned to the bathroom and picked Reeva up as I had been told not to wait for the paramedics, but to take her to the hospital. I carried her downstairs in order to take her to the hospital.
"On my way down ... a doctor who lives in the complex also arrived. Downstairs, I tried to render the assistance to Reeva that I could, but she died in my arms."