PRETORIA, South Africa (AP) ― The murder trial of Oscar Pistorius has been delayed until April 7 because one of the legal experts who will assist the judge in reaching a verdict is sick, the judge said Friday.

Judge Thokozile Masipa announced the delay in court, abruptly ending expectations that the double-amputee runner was about to testify about his fatal shooting of girlfriend Reeva Steenkamp last year.

“One of my assessors is not well, so this court is not properly constituted,” Masipa said. “I suggest that we postpone this matter until the seventh of April.”

Masipa has two assessors who sit on either side of her in the courtroom.

South Africa does not have a jury system, and Masipa will deliver a verdict.

Pistorius faces 25 years to life in prison if convicted of premeditated murder for killing Steenkamp.

Defense lawyers were due to begin their case on Friday after four weeks of prosecution-led testimony.

Pistorius says he shot Steenkamp by accident, mistaking her for an intruder in his home and opening fire through a closed toilet door in the early hours of Feb. 14, 2013.

Prosecutors say he killed her after an argument.