Oscar Pistorius took the stand on Monday and testified about the night he is accused of murdering his girlfriend Reeva Steenkamp.

The Washington Post reported that after pathologist Jan Botha testified earlier in the day, Pistorius took the stand and started by apologizing to Steenkamp’s family and friends.

“I would like to take this opportunity to apologize to Mr. and Mrs. Steenkamp, to Reeva’s family,” he said. ”To those of you who knew her who are in court today.”

The Associated Press noted that the former Olympian then told the court that he has had panic attacks and nightmares since he shot the model on Valentine’s Day last year.

He also said the he has been taking antidepressant medicine and described one night when he hid in a closet after waking up in "a panic."

"I climbed into a cupboard and I phoned my sister to come and sit by me, which she did for a while," the athlete said.

Prosecutors believe that Pistorius murdered his model girlfriend after the two had an argument. However, the track and field star contends that he shot Steenkamp after mistaking her for an intruder. He has plead not guilty to the charges against him.