"He tend to be quiet, rarely communicate and rarely socialize," Brigadier General Dedi told the press at the National Police Headquarters, Jakarta, on Tuesday.
Dedi said before the suicide bombing at the monitoring post, RA left his house without saying goodbye to his parents.
"Not saying goodbye, just going out with (using) motorbikes, (parents) did not know where. Suddenly there was an explosion at the police post," he said.
RA was 22 years old, employed at a private job, unmarried, possessing a senior high school education and living at Wirogunan, Kartasura, Sukoharjo, Central Java.
RA, who officials said was exposed to the radical practices of ISIS, is now stable and being treated in a hospital.
The bombing occurred at Tugu Kartasura Traffic Monitoring Post, Sukoharjo, Central Java on Monday June 3, 2019 at around 22:45 a.m. WIB.
Officials said RA wore a black shirt, jeans and a headset as he walked to the Pantau Tugu Kartasura Post.
Ten minutes later there was an explosion in front of the post, which resulted in the bomber being injured.