The doctor had retired to sleep on a piece of carpet in a seminar room after a marathon 36-hour shift, given the lack of dorms or resting rooms. She was later found bleeding from her eyes and mouth, with injuries to her legs, stomach, ankles, her right hand and finger, according to a doctor's inquest report accessed by Reuters.
Hundreds of protesters gathered in several cities in the San Francisco Bay Area, demanding accountability for the crime and safety for Indian women.
In Dublin, California, about 35 miles (56 km) east of San Francisco, protesters formed a human chain, shouting slogans and waving placards that read "We demand justice" and "Shout it loud, shout it far, justice for R G Kar".
People across ages, including young children and seniors, recited poems and took part in a street theatre.
"While we do want women's safety, this is about the safety of everyone at their workplaces," said Sukalpa Chowdhury, a 39-year-old physician who joined the protests in Dublin.
"How can we have our future generations, who will go to the same institutes, feel safe, get a good education and serve society? That is a big concern for everyone."
At another protest in the Swedish capital Stockholm, scores of mainly black-clad women gathered in Sergels Torg square to sing songs in Bengali and hold signs.
Although tougher laws were introduced after the 2012 gruesome gang rape and murder of a 23-year-old student on a moving bus in New Delhi, activists say the Kolkata case shows how women continue to suffer from sexual violence.
The Central Bureau of Investigation (CBI) are probing the crime but are yet to file charges. The Supreme Court created a hospital safety task force last month to recommend steps to ensure medical workers' safety.