Rio Alex Bulo

Over the years, all the clemency and pardon requests issued by Bulo were denied, effectively cementing his fate. On August 8, 2008, he was brought to the village of Karangtengah, where he was subsequently executing by a 12-member firing squad. His body was then buried in the village of Kejawar. Following his execution, his wife publicly apologized to the victims' families and the community for her husband's actions.

Bulo was initially detained at the Kedungpane Prison in Semarang, but then transferred to one of the prisons on Nusa Kambangan in August 2004. In there, he quickly befriended a fellow convict, embezzler Iwan Zulkarnaen, to whom he became close enough that he allowed him to teach Bulo the Quran. On May 2, 2005, during one such session, Zulkarnaen made a remark that Bulo didn't seem like the type of man to be on death row: in response, Bulo became enraged and started punching him before fatally banging his head against the wall.

On January 12, 2001, Rio entered the Rosenda Hotel in Purwokerto, where he subsequently killed businessman and lawyer Jeje Suraji in room 135 in order to steal his rented Toyota Kijang. The staff were alerted by the commotion, and immediately after Bulo left the hotel, the room was checked. When they entered, the staff found bloodstains on the walls and ceiling, and that Suraji's battered body had been left on the bed and covered with a blanket. This was immediately relayed to the hotel security guards, who managed to detain Bulo while he was still on the parking lot, before eventually handing him over to the police.

On May 14, 2001, the Purwokerto District Court sentenced Bulo to death for his crimes, with him apologizing to the victims' families during the court proceedings. Following the verdict, his crimes were exposed to the public and quickly garnered infamy due to their brutal nature. According to an interview given to Kompas on June 3, 2001, Bulo claimed that he was 'grateful that [he] didn't die while committing a crime, but would welcome dying in the process as a punishment.'

Between 1997 and 2001, Bulo is known to have killed at least 4 people, all of them car rental entrepreneurs. The first victim was in Surabaya, from whom a Sedan was stolen; the other two were killed in Semarang, while Bulo was attempting to steal their Isuzu Panther. Shortly after, a fourth attempt was tried against a man in Yogyakarta, but failed, forcing Bulo to move to Purwokerto.

Antonius Rio Alex Bulo (May 2, 1978 – August 8, 2008), known as Rio the Hammerhead (Indonesian: Rio Martil), was an Indonesian serial killer who killed at least four people with a hammer between 1997 and 2001, and then his cellmate in 2005. For his crimes, he was sentenced to death and subsequently executed by firing squad in 2008.

Little is known of Bulo's background. It is known that he was born on May 2, 1978, in Sleman, and, according to several sources, was reportedly an unruly child who lashed because his parents preferred to pay more attention to their business than him. Due to his erratic behavior, his parents sent him to Jakarta, where he would be raised by his elder, 12-year-old brother. To their dismay, his behavior worsened, especially after his father renounced him because Rio refused to convert to his religion.