An Indian court convicted four men Tuesday of the gang rape and “cold-blooded” murder of a student on a New Delhi bus in a crime that sickened the nation and led to new laws to tackle endemic sex crime.

Judge Yogesh Khanna said the men, who could now face the death penalty, were guilty of murdering a “helpless victim” last December, as he announced that arguments for sentencing of the four would be held on Wednesday.

“I convict all of the accused,” Khanna told a packed courtroom. “They have been found guilty of gang rape, unnatural offences, destruction of evidence... And for committing the murder of the helpless victim.”

The four — Mukesh Singh, Akshay Thakur, Pawan Gupta and Vinay Sharma, aged between 19 and 29 at the time of the crime — had all pleaded not guilty to the charges.

The men, whose faces were shown by the media for the first time on Tuesday, were economic migrants living in or around a south Delhi slum who were drawn to the city to escape grinding rural poverty.

The victim’s parents, who wept in court as the verdict was announced, have led the calls for them to be hanged, saying that they would only find closure if the four are executed.

Their 23-year-old daughter, who cannot be named for legal reasons, died of grievous internal injuries on December 29 in a Singapore hospital after being lured on to the private bus following a cinema trip with a male companion.

After beating up the friend, the gang brutally assaulted her behind tinted windows for 45 minutes before flinging the bloodied and barely conscious couple from the vehicle on a road leading to the international airport.

Amid emotional and unruly scenes outside the courtroom as journalists fought each other for space, lawyers for three of the convicts said they would appeal the verdict while the fourth was considering his options.

“My client was simply driving the bus. He confessed fairly that he was driving the bus but he did not know what went on inside,” V.K. Anand, the lawyer for Mukesh Singh, told reporters.

It was not clear when the four would be sentenced.

A.P. Singh, the lawyer for Akshay Thakur and Vinay Sharma, called the verdict a “political conviction” and said they would appeal, which is likely to take years in India’s notoriously slow legal system.

Mukesh Singh’s mother, draped in a beige saree, fell to Anand’s feet and broke down in tears outside the courtroom.

A juvenile has already been sentenced to three years in a correctional facility, while a fifth adult defendant, bus driver Ram Singh, was found hanging in his prison cell in March while awaiting trial.

“We will not accept anything below the death penalty,” the victim’s father told AFP in an interview last week from his new home in southwest Delhi, which has been given to the family by the government.

“If all four are sentenced to death, I can’t imagine anything being better than that... We will get closure.”

The seven-month trial was held in a special fast-track court in south Delhi, with more than 100 witnesses called to give evidence, including 85 for the prosecution.

The attack sparked weeks of violent street protests across India with seething public anger about sex crimes against women.

It also led to tougher laws being passed by Parliament in March for sex offenders, including the death penalty for rapists whose victims die or are left in a vegetative state.

But savage attacks against women are still reported daily in India’s newspapers and the gang rape of a photographer last month near an upmarket area of Mumbai rekindled public disgust.

“We have tens of thousands of rape cases pending and very few convictions, which doesn’t send a strong message at all,” said Ranjana Kumari, director of the non-profit Centre for Social Research.

During the trial, the prosecution produced DNA evidence, the victim’s dying testimony and statements from the male companion.

In his written judgement on Tuesday, Khanna held that the facts “make all the accused liable for the cold-blooded murder” because the victim suffered internal injuries inflicted by their hands and an iron rod.

In an interview ahead of the verdict, the 28-year-old companion told AFP that the assault was beyond a nightmare.

“I never imagined that one human being could treat another so badly,” he said, before adding: “They wanted us to die.”

A small group of protesters stood outside the court as part of a campaign to push for the death penalty. Some wore black hoods and makeshift nooses, while one held a sign that read “We Want Rape-Free India.”

India has the death sentence for the “rarest of rare crimes,” but does not often carry out executions.