When the police and judiciary cannot be relied on to resolve disputes, rape often becomes a means of retribution. This has been apparent in Hindu-Muslim riots as well as in intercaste conflict. “Rape is a weapon to silence the assertions of the community. A way to teach us a lesson. To show us, including our men, that they are helpless and cannot protect their own women,” said Asha Kowtal, a Dalit activist.

Such thinking seems to have been at work in March, in the state of Haryana, when four lower-caste girls were gang-raped and dumped on a train station platform more than 100 miles from their homes. There is evidence that a conflict between Dalits and Jats precipitated the attack. According to the Indian newspaper Mint, a land dispute led Jats to declare “a social and economic boycott against the Dalits,” perhaps culminating in the gang rape.

We will never be able to address India’s rape crisis if we remain blind to the machinations of caste discrimination. In the past, it has taken gruesome cases of violence to ensure coverage of rape. Indeed, perhaps the only reason the Katra Saadatganj hangings attracted attention was that grisly photographs of the dangling bodies were published in Indian newspapers and circulated on social media, despite complaints by Dalit activists that this was disrespectful.

But we cannot rely on the shock value of particularly horrific cases to lead to change; we need structural solutions. The government should start by amending the 1989 Prevention of Atrocities Act, which is designed to address caste-based violence. The conviction rate under the act is notoriously low — according to a 2012 report, more than half of all cases are closed before they reach the courts. In the case of Mr. Lal’s daughter and her cousin, the police did not register the crime under the act at all. Amendment proposals that would ensure crucial witness protection, more legal support and special courts are sitting in Parliament right now, awaiting approval.

There is no doubt that it was wrong for the police to ask Mr. Lal about caste. But for the rest of us, when it comes to understanding India’s rape crisis, not talking about caste is just as bad.