Johannesburg - Advocate Gerrie Nel’s co-prosecutor Andrea Johnson will lead the State’s case against convicted murderer Oscar Pistorius, the NPA said on Tuesday.Spokesperson Luvuyo Mfaku confirmed this shortly after News24 announced that Nel had tendered his resignation with the authority on Monday and had given them a 24-hour notice period.However, this would not affect the cases that Nel had been working on, Mfaku said."If you noticed, as an institution, we think ahead. We always have three advocates [on a case] to ensure that there is continuity."He was with advocate Johnson, who is a senior deputy and a senior state advocate there. Those people have got intrinsic knowledge of all those matters. They were involved; now they will continue with those matters and they will deliver justice to the people of this country. That is our mandate," Mfaku said.Nel had mentored several prosecutors within the NPA and had shared his experience with them. Many of them were still working in the NPA as senior advocates and were now experts within the criminal justice arena, Mfaku said."So we are not paralysed. He has actually mentored a lot of people."Jail term too lenientIn November last year, the Supreme Court of Appeal in Bloemfontein granted the State – led by Nel and Johnson – permission to argue why it thought Pistorius's six-year jail term was lenient.This was after Nel filed court papers in an attempt to keep the former Paralympic athlete behind bars for even longer for the murder of his model girlfriend Reeva Steenkamp in 2013.On July 6, Pistorius was sentenced to six years in prison by Judge Thokozile Masipa. In her sentencing, Masipa said, while the crime was serious, a long term of imprisonment would not serve justice in this case.In October 2014, Masipa had sentenced Pistorius to five years behind bars for culpable homicide. On December 3, 2015, the SCA ruled that it agreed with the State and overturned Masipa's verdict, changing it to one of murder.Pistorius shot Steenkamp four times through the locked door of the toilet in his Silver Woods Country Estate home in the early hours of February 14, 2013.He claimed he thought there was an intruder behind the door, about to emerge and harm him, and that Reeva was still in bed.'Fiery, passionate'In an interview with the City Press, former NPA boss Vusi Pikoli previously described Nel and Johnson as lawyers who were not scared of "difficult cases" when others within the authority were getting "scared and started moving away" from such cases.He described Johnson as a "fiery" and "passionate" prosecutor."She is another fiery prosecutor. She knows her job and she’s very passionate," he said.It was under Pikoli’s leadership that Nel and Johnson had prosecuted former police chief Jackie Selebi.However, after the ANC’s Polokwane conference, Nel was sidelined when President Jacob Zuma appointed his long-standing enemy Advocate Nomcobo Jiba as acting head of the NPA, City Press reported at the time.Nel was only given the Pistorius case after being contacted by a senior prosecutor in Pretoria, who panicked because nobody was available to take the case at short notice. Nel was available."If I were going up against Nel and Johnson, I would make sure of my case," Pikoli said.