The killers in three high-profile murder cases in Delhi, who are serving life terms in jail, will not walk free, a board reviewing their sentences has decided. Manu Sharma, convicted for the murder of Jessica Lal, Santosh Singh, the killer of law student Priyadarshini Mattoo and Sushil Sharma -- who killed his wife Naina Sahni and tried to dispose of her body by burning it in a tandoor -- will have to serve their sentences, said the board, which took a call on the early release of convicts in more than 100 cases.