Hussein said the suspect, referred to only as “Ah Boy”, was believed to have consumed methamphetamine, which made him “trigger-happy” before committing robberies, break-ins and other crimes.
“Investigations revealed that the suspect, in his 30s, was involved in both drug distribution and consumption. His drug use had a profound impact on his behaviour, driving him to act that way.
“We believe he was using methamphetamine. A blood test conducted on his body confirmed he was positive for drugs,” he told a press conference after an event in Shah Alam today, Berita Harian reported.
Hussein also said the suspect was previously involved in gang robberies but had been operating alone over the past year or two, possibly because he could not get along with his former accomplices.
“In the past year or two, he committed robberies and thefts for his own needs. When he ran out of money, he would commit another crime — that was his pattern,” he said.
Hussein also revealed that the suspect had used two semi-automatic pistols, a Sig Sauer and a Retay, in his criminal activities.
He added that investigations are ongoing to determine how he obtained the firearms, but police believe he acquired them domestically.
Last week, FMT reported criminologist Shahul Hamid Abdul Rahim as urging the police to find the gun supplier in the Setia Alam shooting as it could expose illegal firearms networks if the weapon was bought on the black market.
The suspect had fired several shots at a janitor in the incident on Feb 8, injuring him in the legs. He also held a family at gunpoint, forcing them to drive him out of the mall before escaping.
Hussein previously said the gunman was involved in five other crimes before he was shot dead at a hotel in Pulau Ketam, off Klang, on Tuesday morning.
He said the suspect travelled to Melaka, Banting and Sabak Bernam before finally putting up for the night in Pulau Ketam. It is said he was planning to get a boat to take him to Thailand from there.
Hussein said the suspect had committed 15 crimes in total — nine crimes before the Setia City Mall shooting and five after.