Dyankrishnan, eminent lawyer and a counsel in Delhi High Court, has himself volunteered to do it free of cost, a Delhi Police statement said here.
He will be assisted by two juniors.
Investigators said they will file the chargesheet in the court on January three.
Police have slapped murder charges as well as sections 201 (destruction of evidence), 365 (kidnapping or abducting), 376 (2)(g) (gang rape), 377 (unnatural offences), 394 (hurting in committing robbery) and 34 (common intention) of IPC.
The girl, who was gangraped and brutally assaulted allegedly by six men in a moving bus in south Delhi on December 16, died early this morning in a Singapore hospital.
