The 2019 Bærum murder and mosque attack occurred on 10 August 2019 at the Al-Noor Islamic Centre in Bærum, Norway, about 20 kilometres (12 mi) west of the capital city Oslo. Philip Manshaus, a 21-year-old Norwegian man, murdered his 17-year-old adopted sister Johanne Ihle-Hansen at their home. He then drove to the mosque and shot his way through the glass door before opening fire, hitting no one; the mosque was almost empty, as prayer had ended. He was subdued by three elderly worshippers after a scuffle, and turned over to police. He had attempted to livestream the shooting, but failed.
Manshaus was fixated on far-right conspiracy theories and mass shootings, and had been investigated in 2018 after a tip was filed over his neo-Nazi views. The tip was not followed up on, as it was deemed to be vague and lacked signs he was planning a violent attack. He murdered Ihle-Hansen due to her being of Asian ethnicity, and the mosque shooting was done to intimidate Immigrants; the attack was inspired by the Christchurch mosque shootings, which had occurred earlier in the year. The guns were stolen from Manshaus's father.
Manshaus was convicted of murder and committing an act of terrorism, and in 2020 was sentenced to 21 years preventative detention, an order which, in Norway, can be extended indefinitely. The case was reopened in 2024, after experts assessed that Manshaus had likely been psychotic since 2017, including while the crime was committed. In October 2025, Manshaus was resentenced to 21 years in prison, this time without extended detention, with the court citing his abandonment of far-right extremism and lack of previous convictions for violent crimes as its rationale.
Philip Manshaus (born (1997-08-29)29 August 1997), a 21-year-old Norwegian resident of Bærum, perpetrated the attack. His biological mother and grandmother died by suicide when he was four years old. He had attended the liberal arts craft school Fosen Folkehøgskole (a folk high school), which has a reputation as a leftist and alternative institution. He has two older brothers. In his youth, he was known to have many different phases; his step mother noted he would often become fixated on strange things and become extreme about them. He had a history of experimenting with drugs; at the age of 15, he drove while on LSD and got into a car accident. He had been in a gay relationship with another boy in Oslo's emo scene.
Johanne Zhangjia Ihle-Hansen (born 18 June 2002) was born in Jiangxi, China, and adopted at 9 months old by Manshaus's stepmother. At her high school, she majored in communications and media. She had a boyfriend from Portugal, who she hoped to move in with after finishing her schooling. She aimed to become a journalist. Manshaus and Ihle-Hansen had previously been very close, and Manshaus was said to be protective of her; while coverage described them as adopted step-siblings, they viewed each other as full siblings and she was a fully accepted member of their family. A childhood friend of both siblings described Ihle-Hansen as looking up to Manshaus.
Beginning in the summer of 2017, Manshaus had been interested in conspiracy theories. He openly discussed with his friends antisemitic conspiracy theories about the Holocaust and attempted to convince them of his beliefs, which led to his friends avoiding him. Other students noticed a change in his personality and worried that he would kill someone, or that Manshaus would get killed; he became increasingly Christian and radical. His internet activity included him reading about school shootings in Finland and in the United States; he was interested in "alt-right" and neo-Nazi materials online, reading among others the works of Jordan Peterson, James Mason's Siege, and the manifesto of Norwegian terrorist Anders Behring Breivik.
On 18 June 2018, a tip about Manshaus was sent to the PST, the domestic intelligence service in Norway, stating that he had far-right views and that his friends called him a neo-Nazi. After coordinating with the local police department, Oslo Police District, they found that the tip was vague and showed no signs Manshaus had any plans to commit a violent attack. Manshaus was not interviewed and the tip was not followed up on. Manshaus's family were not informed of the report. He frequently visited imageboards, which contributed to his radicalization.
Their family worried about him, and after Ihle-Hansen told their mother of her concerns, Ihle-Hansen suggested they try to take him along with them for normal activities and introduce him to non ethnic-Norwegians so he could make friends. However, she was unsettled and uncomfortable with his behavior. Ihle-Hansen sent various messages to others through the messaging app Discord expressing frustration and concern over Manshaus's views, and said she did not feel safe. He became increasingly extreme in his anti-immigration and antisemitic attitudes, and became cold towards Ihle-Hansen. He refused to greet her and said cruel things to her. He told Ihle-Hansen that she and her boyfriend should not have children because it would be "race mixing", and said that she was not his sister because to be his sister "she would have had to be human". He also made fun of her for her skin color, knowing she was insecure about it.
In the weeks before the attack, Manshaus tried to join the neo-Nazi Nordic Resistance Movement, but due to an internal split in the organization and delays in their membership system he never got beyond the first of two planned initiation interviews. Manshaus joined a gun club and indicated that he would try to get semi-automatic weapons. At one point, Ihle-Hansen was delivered a package for him that contained a bulletproof vest.
On 15 March 2019, Brenton Tarrant committed an anti-Muslim terrorist mass shooting in Christchurch, New Zealand, killing 51 people and livestreaming the attack. Along with the shooting Tarrant self published a manifesto; Manshaus witnessed the livestream around the time of the attack but this did not have an impact, and he only read the manifesto on 2 August 2019. After Manshaus read it, it deeply affected him, and he slept and ate little for several days; he viewed it as a "call" for him to "take action". Manshaus drafted a manifesto, but did not finish it. Manshaus's family noticed he had attached newspaper clippings about the Christchurch mosque shootings, a swastika, and information on other terrorist attacks to his wall, and hid it behind a Norwegian flag, after which Ihle-Hansen became afraid he would hurt someone. After he learned his stepmother was considering reporting him to the PST, he took them down, and tried to make it seem as if he was no longer far right.
On 8 August, Ihle-Hansen told a friend that it was difficult at home because "my brother hates me", and said that she was afraid of Manshaus. The day before her murder, she texted her boyfriend and expressed frustration with Manshaus's racist views, and told him that his room was full of "Nazi propaganda and newspaper clippings about mass shootings". She said she felt unsafe and that what she was going through was "madness". She also said he was then listening to a speech that expressed racist views against those of Chinese descent. After Ihle-Hansen expressed to her friends her concerns, they decided to inform Ihle-Hansen's mother and inform the police or PST. When she was informed on the morning of 10 August she agreed to inform the PST.
Manshaus had a planned list for the attack, listing his weapons and the address of the Islamic Center, as well as "MURDER AT HOME" in all capital letters. He later said that he had decided to kill her because she was not white, and a result he believed that if she was alive, their parents would be deemed "race traitors" during what he viewed as an imminent race war, and that she "represents a group that threatens my people". The mosque attack was planned to intimidate Immigrants in Norway, and to kill "as many non whites as possible".