LONDON — The murder case of Farzana Parveen, it seemed, could hardly have turned more tragic or gruesome: a 25-year-old pregnant woman, bludgeoned to death with a brick by family members on a busy street, for having married the man she loved.

Then, in recent days, came a dark twist.

It turned out that Ms. Parveen’s husband, Muhammad Iqbal — who had been photographed over the bloodied body of his wife, his face etched with grief — had been a black widower five years earlier. Mr. Iqbal, 45, said he had killed his first wife to be with Ms. Parveen, and later won his freedom, legally, using an Islamic provision of Pakistani law. “I strangled her,” he said of his first wife in a telephone interview. “I liked Farzana since she was a child.”

The attack on Ms. Parveen in Lahore, Pakistan, on Tuesday has generated global outrage, a public intervention from Prime Minister Nawaz Sharif and an unusually aggressive effort by the Pakistani police to pursue those responsible. By Friday morning five men, including Ms. Parveen’s father, had been arrested, but officers were still searching for her two brothers, one of whom faces accusations of beating her to death with a brick.

To some, Ms. Parveen’s death was a sign of growing religious intolerance in Pakistan, an impression burnished by news media reports of a stoning, an image with echoes of Taliban-era Afghanistan.