Sunakim alias Afif is the most recognisable of the four militants who mounted the brazen attack in Central Jakarta, after images of him shooting randomly into crowds and at police officers last Thursday went viral.
The 34-year-old Indonesian militant, loyal to the Islamic State in Iraq and Syria (ISIS), may now be proof the country's penitentiary system may be flawed.
This after it emerged that he was given early release for "good behaviour" while serving time for illegal possession of firearms and joining a paramilitary training camp in Aceh. The camp was backed by Jemaah Islamiah spiritual leader Abu Bakar Bashir as well as extremist ideologue Aman Abdurrahman, no less.
He had been sentenced by the West Jakarta District Court to seven years in prison and The Straits Times understands he was supposed to have been released only in December this year. However, the Law and Human Rights Ministry cut his sentence by two years, The Jakarta Post reported yesterday.
The spokesman for the ministry's directorate-general for penitentiaries, Mr Akbar Hadi, confirmed that Sunakim had received various types of remissions while at the Cipinang Penitentiary in East Jakarta between 2010 and last year. The sentence reductions included provisions for the Idil Fitri holidays and others granted by the government to all inmates at 20-year intervals.
The remissions were given even though Sunakim apparently refused to join the prison's deradicalisation programme aimed at preventing imprisoned terrorists from committing further violence.
"We cannot force an inmate to join a deradicalisation programme, it is just an option," Mr Akbar added. "The point is that if a penitentiary releases a convict, then he or she has already met the necessary requirements. We never release a convict without basis."
Sunakim was not the only one involved in last Thursday's siege who had gone through the penitentiary system.
Muhammad Ali, who at 39 is the oldest among the four now-dead militants, had also been jailed for robbing a bank in Medan in 2010 to fund terrorist activities.
Experts have long said that Indonesia's prisons remain one of its weakest links in its war on terror - a chink in its armour that has once again been shown up to deadly effect.
Over 165,000 people are locked up in Indonesia's prisons. More than 250 of them have been convicted of terrorism-related charges and are housed in 44 prisons across the country.
Counter-terrorism and security expert Susan Sim said previously that at least 40 former terror convicts returned to militancy within two to three years of parole in Indonesia.
"The numbers obviously do not tell the full story and, in any case, are debatable as there is no nationwide database in Indonesia," she told The Straits Times last year. "What should give cause for concern is what these recidivists have been doing."
The Jan 14 attack might be the extreme of what they could end up doing - embracing ISIS and mounting a strike on soft targets in their homeland. But the advent of ISIS in the region in recent years means that Indonesia has had to manage its war against terror on two fronts.
First: preventing local militants returning from the Middle East, after receiving training or fighting alongside ISIS, from spreading their extremist ideology back home. And second: ensuring that those who have served time in jail for terrorism do not relapse.
Failing on either front is not an option for a country that has, before the attack on Jan 14, already suffered more than a dozen terrorist attacks in the last 15 years, including the 2002 Bali bombings that killed 202 people.
Ms Sim's research showed that in recent years, five recidivists were killed in shoot-outs with the police, at least one is known to have joined ISIS in Syria, while several others started or joined new extremist groups that have been targeting police officers. One of them is Abu Wardah, better known as Santoso, leader of the East Indonesia Mujahidin and Indonesia's most wanted terrorist.
The authorities can now add Sunakim and Ali to that list.
Santoso, Sunakim and Ali come from a pool of more than 600 Indonesians freed after serving time for terror-related activities.
National counter-terrorism chief Saud Usman Nasution said recently that Indonesia has a "big job to do" to keep tabs on these men. Perhaps it would be wiser to fix the problem at its source - before they are released.
Repairing an entire prison system plagued by decades of malaise and neglect will not be easy, but last Thursday's attack may just give the country the impetus to do so.
Correction note: An earlier version of this report stated that militant Sunakim alias Afif's age was 32. A source, who asked not to be named, has since clarified that he was 34.