The man who opened fire at a mosque near the Norwegian capital of Oslo Saturday had gone online to express far-right views, according to local police. Although not officially identified, reports claim the alleged gunman is Philip Manshaus, 21. The Norwegian citizen was reportedly wearing body armor and was heavily armed when he shot through a glass door to get inside the Al-Noor Islamic Center.

The gunman was overpowered by a 65-year-old worshipper, who was injured in the confrontation. Officials say the shooting could have been much deadlier if the suspect had arrived only a few minutes earlier. There were more than a dozen people inside the mosque a mere 10 minutes before the suspect arrived. But by the time he got there, only three older men remained inside, and one of them managed to disarm the shooter.

After the mosque shooting, police found the body of the gunman’s 17-year-old stepsister at his home in Baerum, which is west of Oslo. The gunman has been charged with the murder of the woman and is facing an attempted murder charge for the mosque shooting.

Police in Oslo said Sunday that they’re investigating the shooting as terrorism because of the gunman’s apparent intent to inspire fear. But they emphasized that there is no evidence he was part of a larger network. Authorities said the suspect had expressed far-right views, including admiration for Vidkun Quisling, Norway’s leader who collaborated with the Nazis during World War II.

Hours before the attack, a user of the same name as the alleged gunman posted on the 4chan messaging board expressing admiration for the gunman who killed 51 people at two New Zealand mosques earlier this year. The post included a meme that described that gunman as a “saint” and praised the alleged El Paso, Texas, shooter for “reclaiming his country.” The post was made on a new messaging board called Endchan and the older site 4chan.

Authorities ordered police to guard mosques in the city. As Muslims celebrated the beginning of Eid al-Adha Sunday, many non-Muslims stood outside mosques in Oslo to stand guard, reports the New York Times. “This is not supposed to happen in Norway,” Prime Minister Erna Solberg said. “Norway should be safe. All places of worship shall be safe.”

This post has been updated with new information since it was originally published.