Extremist groups have infiltrated universities in order to lure new recruits, experts warn. [Dwi Oblo/Reuters]

No sooner had the judge read out the sentence against convicted terrorist Hendi Suhartono than a woman's sobs and plaintive wails filled the courtroom.

"Don't leave Mother," she cried. "Pity, pity." Indonesian news reports said she was around 50 years old, and clad in a purple blouse and veil.

The convicted man spoke quietly with his lawyers and then exited the courtroom without stopping to console her.

A judges' panel delivered its verdict on Monday (March 5th), finding the 32-year-old Suhartono guilty of carrying out acts of terrorism. The 12-year jail term he received was less than the 18 years demanded by prosecutors.

Suhartono once seemed poised for a life far different from that of a convict. He attended the prestigious Syarif Hidayatullah State Islamic University, where he graduated with a degree in philosophy. Later, he opened a printing business.

It was during his student years, however, that he fell in with Islamist militants associated with the outlawed Negara Islam Indonesia (NII) movement. Police say the extremist group has turned its attention in recent years to luring new recruits from among the country's educational institutions.

While universities have always been arenas for often fiery political debate, what's new is that radical groups see an opportunity to harness that energy for more sinister purposes, experts say.

A May 2011 special report in The Jakarta Post cited top university officials as expressing concern that the trend is on the rise.

"Such a phenomenon has ignited concern that these hardline groups have been cajoling students into supporting future violence and intolerance," the paper quoted National Anti-Terrorism Agency (BNPT) head Ansyaad Mbai as saying.

Last year's discovery of the book bombing plot and a related bid to blow up a Jakarta church focused public attention on what some are calling the new face of Islamist militancy.

Suhartono is one of seven men, including apparent ringleader Pepi Fernando, to have been convicted so far for their roles in a wide-ranging conspiracy targeting moderate Muslims, secular institutions, and Christians.

Police say Suhartono not only helped make the bombs sent to rock musician Ahmad Dhani, National Narcotics Agency chief Gories Mere, youth organisation head Yapto Suryosumarno and liberal politician Ulil Abshar Abdalla, but even penned forewords to the books in which the explosives were concealed.

He then watched on TV as one of the bombs went off while police tried to defuse it, injuring an officer's hand.

In April 2011, Fernando and his group hid 150kg of explosives – with several of the bombs placed near a gas pipeline to amplify the carnage – near Christ Cathedral Church in Serpong. Police said the terror group had planned to use mobile phones to trigger massive blasts to coincide with the church's Good Friday celebrations.

Global TV cameraman Imam Mochammad Firdaus, convicted on the same day as Fernando and Suhartono and sentenced to three years in jail, allegedly planned to film the attacks so the media-conscious terrorists could publicise their actions.

The conspiracy fell through, though, after authorities discovered the explosive devices and arrested 19 men in connection both with the planned church attack and the March book bombs.

Terrorist ringleader Fernando – sentenced on Monday to 18 years -- told police during his interrogation that the group decided to carry out attacks because they were angry at the government's refusal to turn Indonesia – the world's largest Muslim democracy -- into a strict Islamic theocracy.

Imposing their view of Islam on the country has long been the goal of NII and related extremist groups, including Jemaah Islamayah, whose main ideologue, Abu Bakar Bashir, has been sentenced to 15 years in jail on terrorism charges.

"NII has a long history, and we're still at war with its seemingly proliferating ideology. It'll be a long fight until we can win," said Al Chaidar, a terrorism expert and former member of the extremist group, in comments quoted by The Jakarta Post.