Bangladeshi women alarmed by emboldened Islamists
His alleged victim was a student who enthusiastically supported the youth-led uprising that overthrew the Muslim-majority nation's autocratic government last year.
That young woman, after receiving a torrent of violent threats from religious hardliners emboldened by the political upheaval, now wonders whether she made the right choice.
"A perpetrator was freed because of a mob," she said in a social media post.
"You can't imagine the number of rape and death threats I've received," added the woman, who cannot be identified due to Bangladeshi laws designed to protect sexual harassment complainants from retribution.
"We made a mistake by joining the movement. So many people sacrificed their lives in vain."
Ex-premier Sheikh Hasina, ousted in last August's revolution, took a tough stance against Islamist movements during her 15-year tenure.
Her government was blamed for gruesome human rights abuses and for many, her departure heralded change.
Since her exit, the hardline religiously fuelled activism that Hasina's government had driven underground has resurfaced.
Much of it is directed at Bangladeshi women, accused of failing to act with sufficient modesty.
Arnab, who works at the library of the prestigious Dhaka University, was accused of accosting a student on campus, saying that her choice of attire did not sufficiently cover her breasts.
The student complained, and Arnab was arrested.
Supporters of Arnab who believed he had acted in appropriate deference to his religious convictions surrounded the police station and demanded his release.
They yielded when a court quickly bailed Arnab -- something the female student attributed to mob pressure.
A spokesman for Dhaka's police force, Md Talebur Rahman, told AFP that Arnab was still under investigation, and also acknowledged the menacing behaviour his victim had faced.
"She can lodge a complaint against those who have been threatening her," Rahman added.
'A crisis'
It is far from an isolated incident.
Several women's football matches were cancelled this year after pitch invasions by Islamists angry at women's participation in sport.
Two women were briefly taken into protective custody by police this month, after an altercation that began when they were harassed for publicly smoking cigarettes by a crowd of men on their way to pray at a mosque.
Islamist groups have also demanded organisers of religious commemorations and other public events remove women from the line-up.
Dhaka University student Jannatul Promi, 23, said that the rising incidences of harassment had left young women feeling unsafe.
"We are going through a crisis," she said. "The other day, I was waiting for the metro when a man approached me and asked if I should be outside without a veil. As soon as I responded, more people joined him against me."
Fellow student Nishat Tanjim Nera, 24, said the authorities had failed in their duty.
"Harassment incidents are happening repeatedly, but there is no redress from the government," she said.
'Complete denial'
Several recent cases of sexual violence have captured public attention.
An eight-year-old girl died Thursday from wounds she sustained during a rape days earlier -- a case that prompted days of protests and vigils by women in Dhaka and elsewhere.
Such is the level of public anger that police have begun transporting rape suspects to court in the middle of the night, fearful of attacks.
Nobel Peace Prize winner Muhammad Yunus, who leads the interim government which replaced Hasina, condemned the "horrific acts of violence" against women.
"This is deeply concerning and completely at odds with our dream of building a new Bangladesh," he said.
Yunus's administration has struggled to restore law and order, with many police officers refusing to return to work and the army brought in to help.
It has since last month also directed scant police resources to a sweeping crackdown, dubbed Operation Devil Hunt, against gangs allegedly connected to Hasina and working to foment unrest.
Maleka Banu, of the feminist campaign group Bangladesh Mahila Parishad, said those resources would have been better spent on trying to curb sexual violence.
"What good is it for the government to simply express concern? We expected action," she said.
"After Sheikh Hasina's fall, a series of violent incidents followed. The government was in complete denial... Now, they claim the fallen dictator is behind every crime."