Oscar Pistorius will remain on bail while he awaits setencing on 13 October, having today been found guilty of culpable homicide for killing his girlfriend Reeva Steenkamp on Valentine's Day 2013.

Yesterday Judge Thokozile Masipa acquitted him of the two murder charges, but found him guilty of the lesser charge of culpable homicide, which in British law equates to manslaughter.

Pistorius was today also acquitted of firing a gun through a car sunroof and of illegal possession of ammunition. However, Judge Masipa found him guilty of firing a gun in a restaurant, which she said, showed a "reckless disregard" for the safety of patrons.

Although there is no minimum sentence for culpable homicide, he could face up to 15 years in prison.

Pistorius was acquitted of the murder charges because the onus was on the state to prove guilt beyond all reasonable doubt.

The judge found that, despite his contradictory accounts, his behaviour after Steenkamp's death was not consistent with murder. She pointed to his prompt calls for help, calling 999 and security, praying and attempting to resuscitate her.

Nonetheless she found him guilty of negligence in failing to consider the consequences when he fired four gunshots through the locked bathroom door.

The Olympian and Paralympian maintains that he mistook Steenkamp for an intruder when he fired the gun in the early hours of the morning. The prosecution held that he murdered his girlfriend of three months after they had argued.

Steenkamp, a model and law graduate, was 29 when she died. Pistorius, 27, pleaded not guilty to all the charges against him – murder, two additional counts of shooing a firearm in public and the illegal possession of ammunition.

In summarising the trial, Masipa said that there were inconsistencies, both in the testimonies of witnesses who said they heard screams and gunshots, and in Pistorius' account. She described Pistorius as a 'very poor witness' for his contradictions under cross-examination.

However, the judge said that the "The state clearly has not proved beyond all reasonable doubt that the accused was guilty of premeditated murder. There are just not enough facts to support such a finding."

Pistorius looked anxious in court and cried as the summary was read. He broke down in tears several times during the trial, and he vomited in the dock in March when graphic details were given of the victim's injuries.

Steenkamp and Pistorius were known to share a Christian faith. The athlete, who has 1 Corinthians 9:26-27 tattooed on his back, referenced his faith during the trial, which began on 3 March. He was seen holding rosary beads in the courtroom, and said: "My religion is what's gotten me through this last year... my God is my refuge."

On 7 April, when Pistorius took the stand for the first time, he apologised to the Steenkamp family, saying: "I wake up every morning and you're the first people I think of, the first people I pray for. I can't imagine the pain and the sorrow and the emptiness that I've caused you and your family. I was simply trying to protect Reeva. I can promise that when she went to bed that night she felt loved."

The prosecution showed footage of Pistorius shooting a watermelon, comparing it to shooting someone in the head. Prosecutor Gerrie Nel also referred to a time when Pistorius had fired his gun through the sunroof of his car after being stopped by police.

They also highlighted a message that Steenkamp sent to Pistorius a few days before the shooting in which she said she was afraid of Pistorius. "I'm scared of you sometimes and how you snap at me and how you will react to me," she wrote.

In May, forensic psychiatrist Dr Meryll Vorster, a defence witness, said Pistorius suffered from general anxiety disorder, partly as a result of his double amputation, which could have affected his decision making at the time of the shooting.

The trial was then postponed while Pistorius underwent a month-long psychiatric evaluation. In July he was found to be suffering from post-traumatic stress disorder, but no mental illness at the time of the incident that would have prevented him differentiating between right and wrong.

In mid-July Pistorius returned to Twitter, having not used the social media site since the anniversary of the shooting. He posted a few spiritual messages, including an image with the prayer, "Lord I ask that you bathe those who live in pain in the river of your healing."

Steenkamp's family have also talked about the importance of their faith in dealing with the tragedy. Mike Steenkamp, Reeva's uncle, has spoken of his desire to forgive Pistorius face to face.

And in an interview with Hello! magazine in July, June Steenkamp, Reeva's mother, said: "She'll only rest in peace when this is over. I trust that God will prevail and justice will be done. All we want is the truth."

"I don't hate Oscar," she said, "I've forgiven him. I have to – that's my religion."