Most Hindus don’t commit or approve such crimes (really, THEY DON’T) but they ar getting prevalent in areas where Christians have successfully evangelized non-caste and tribal people. There are long-held tensions such areas, and fears that the tribals, now Christianized, will now gain the ascendancy.
Mrs. Don-o — while you are correct about tribal and caste matters playing a role, it may not be true in Kerala — Kerala is about 30% Christian (mostly the ancient MarThoma church — the Church of the Apostle Thomas — or derivatives). In the south a lot of the issues have been because, allegedly, pastors print materials calling hindu gods and goddesses as demons.