Pretoria - Oscar Pistorius will today face a charge of culpable homicide after being acquitted of murdering his model girlfriend Reeva Steenkamp - a shock decision that legal experts described as too lenient.

Judge Thokozile Masipa on Thursday found the double amputee not guilty of premeditated murder – even after describing Pistorius as a "very poor witness" who was "evasive" when questioned about the events of Valentine’s Day 2013.

"The State clearly has not proved beyond reasonable doubt that the accused is guilty of premeditated murder," Masipa told the Pretoria High Court, before adjourning for the day.

Some of South Africa’s legal experts said they were shocked by the verdict.

"I think she's going to get quite a lot of criticism from the judiciary and the legal system," Martin Hood, a criminal lawyer, told eNCA.

"The consensus among the legal community was that he is guilty of murder," the Johannesburg-based lawyer added.

"This could really open the door to systematic abuse of our legal system by people who shoot their partners and claim self-defence."

Masipa seemed to lean towards finding Pistorius guilty of culpable homicide before the abrupt adjournment.

Steenkamp's parents left the courtroom with stony faces.

Johannesburg lawyer David Dadic said he and other legal professionals "are quite stunned by the decision... that the death behind the door, irrespective of who the victim was, was not foreseeable."

However, experts also expect that Pistorius will be convicted on separate charges of twice discharging a firearm in public and ammunition possession, for which he may be jailed, lose his licence or face a fine.

Photo caption: TOO LENIENT... Some legal experts believe Judge Masipa was too lenient when she found Oscar Pistorius not gulity of premeditated murder.