His assassination, which followed months of personal threats, casts a long shadow over the prospects of a democratic and pluralistic Pakistan -- an ideal that the 42-year-old Catholic politician struggled for.
Two months ago, just kilometers from where Bhatti was assassinated today, fellow Pakistani People's Party stalwart and Governor of Punjab Province Salman Taseer was gunned down by his bodyguard. Both men had sought changes in Pakistan's blasphemy law.
Critics see the law as a controversial measure. Anyone accused under the law of speaking ill of Islam and the Prophet Muhammad is charged with a crime and faces the death penalty. Activists say the vague terminology has led to its misuse. Most blasphemy cases in Pakistan are intensely politicized and non-Muslim Pakistanis are live in fear of being targeted under the law.
Michelle Chaudhry, a close friend of Bhatti, says that he was committed to his life-long struggle seeking equal rights for Pakistan's minorities. She told RFE/RL's Radio Mashaal that he became an activist soon after finishing high school.
"He was totally committed to the cause, very brave. In fact just a few days ago he started receiving threatening calls," Chaudhry said.
"I told him just a few days ago, 'Shahbaz you need to hike up your security because these people are not going to stop at anything.' And he told me, 'If my God is with me and Jesus Christ is with me, no security guard can protect me more than Jesus can protect me."
'Most Committed Person'
Bhatti hailed from a Roman Catholic family in Faisalabad, an industrial and commercial hub in eastern Punjab Province. He inherited political activism from his father and formed his own political organization, the Christian Liberation Front, which in 1985 he merged into a new coalition of non-Muslim political activists called the All-Pakistan Minorities Alliance.
Unlike many non-Muslim Pakistani politicians, Bhatti promoted the inclusion of minorities in the mainstream. He joined the current ruling Pakistani People's Party for its liberal and pluralistic credentials in 2002 and was elected to the national legislature on its ticket in 2008.
In his portfolio as the federal minister of minorities, he actively promoted interfaith harmony and understanding. About 4 percent of Pakistan's 180 million people are non-Muslims, with Hindus the predominant group, followed by some 3 million Christians, most of whom are extremely poor.
Bhatti was recognized internationally for his work and was honored in Finland and Canada. In 2009, the U.S. Commission on International Religious Freedom awarded him a first-of-a-kind medal.
Cecil Chaudhry is a former fighter pilot and human rights campaigner who knew Bhatti since his student days in the 1980s. He describes him as "one of the most committed persons that I have come across in my life," who sacrificed everything to end discrimination and oppression against minorities.
"He was the most vocal person in the country right now as far as the rights of minorities were concerned," Chaudhry says. "And as far as the blasphemy laws were concerned. And that's why he was targeted by the extremists."
Bhatti's killing has been widely condemned in Pakistan and internationally. He never married and left behind a family of four brothers, one sister, and an ailing mother, whom he visited every morning.
Abubakar Siddique is a senior correspondent in Prague and Majeed Babar is a correspondent for RFE/RL's Radio Mashaal