One of six suspects held over the gang rape and murder of a student in India is to undergo bone tests to determine whether he is old enough to answer for the crime.
Murder convictions carry the death penalty in India. However, only those aged 18 or more can be put on trial.
If the suspect is found to be underage, it is unclear whether he could still be tried for rape, which carries a life sentence.
The six males are jointly accused of raping and killing an unnamed 23-year-old woman on a bus in Delhi on December 16.
The victim was airlifted to Singapore for emergency treatment, but died on Saturday.
She was cremated in Delhi the next day. Her ashes were set to be submerged in the holy river Ganges near her home town in the northern state of Uttar Pradesh, in accordance with Hindu customs.
Indians have been demanding the death penalty for those responsible, holding demonstrations almost every day since the attack.
Protesters and politicians from across the spectrum called for a special session of Parliament to pass new laws to increase punishments for rapists - including possible chemical castration - and to set up fast-track courts to deal with rape cases within 90 days.
Thousands of people have lit candles, held prayer meetings and marched through various cities and towns to express their grief, and to demand stronger protection for women and the death penalty for rape.
The protests continued on Tuesday, ahead of the first court appearance for the six suspects on Thursday.
Details of the charges run to more than 1,000 pages, according to reports, and some 30 witnesses are named in the prosecution's documents.
On Monday, the Indian army and navy cancelled their New Year's celebrations, as did Sonia Gandhi, the head of the ruling Indian National Congress party.
Several hotels and clubs across the capital also decided not to hold their usual parties.