A pregnant woman and her husband were brutally murdered and their bodies displayed outside her father's house to 'restore the honor' of the father's family. This is due to the caste system, which is designed by the privalaged (upper caste men) to maintain this state of affairs. In the Jat caste in this area, there is a taboo against people from the same village marrying. A group of local men decided that they were entitled to pronounce and carry out a death sentence on the couple who believed otherwise and who married for love instead of for the convenience of the already privalaged. This group may or may not have included the woman's own father, who pleaded guilty to the murders. There is some speculation that he might not have been involved but confessed to show his approval of what had happened.
The villagers are proud of what they have done.
The origin of the caste system in India is ambiguous and may pre-date modern religions, although it seems to be agreed that they lie in the protection of status for the interpreters of religion (priests). However, the system's modern-day connection with religion is quite clear. Hindu scriptures specifically prescribe castes and the practice of Hinduism and other religions including Islam and Christianity strongly re-enforce it in many regions. Devout Hindus, particularly in rural areas, believe that the caste system is divinely ordained. As Indian law is secular, there are no legal punishments for transgressions, but vigilantism is considered just and moral by many. One of the most pernicious mechanisms used by religion to keep the caste structure in place and the privalages of the upper castes intact is the notion of karma, which is a direct result of Hinduism.
The following quote is from the physicist Steven Weinberg. It tends to be over-used, but I have no hesitation in repeating it here:
"With or without religion, you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion."
The people who carried out this atrocious murder are probably otherwise good people who would abhor violence in any other case. However, they were able to use their religion to justify murder. And note that they didn't just kill the couple quietly and humanely; they beat and kicked the woman savagely (I don't know whether they did the same to the man) before strangling them both.
I should point out that practices of this kind are mostly restricted to rural areas, where they are not particularly uncommon. It happens much less in cities, in which the secular Indian laws are more thoroughly enforced and discrimination of any kind on the basis of caste is more consistently punished.
Some key quotes from the article:
"violent repression of [cast transgressions] has risen in tandem as upper caste Jat men fight to hold on to power, status and property."
"We would not have had a face to show if we had not done this. It was the act of 'real men'."
"Nor do politicians ever renounce the practice, Alam added, because if they did, 'they would not win elections'. "
"The people who have done this should get an award for it," said 48-year-old Satvir Singh. "This was a murder of morality."