On 27, October, 2018, Robert Bowers, then 46, allegedly walked into the Tree of Life Synagogue in Pittsburgh, Pennsylvania, and began shooting at worshippers. He allegedly killed 11 people before he was shot and wounded and surrendered to police. Mr Bowers now faces 63 federal counts, including 11 counts each of obstruction of free exercise of religion resulting in death as well as hate crimes resulting in death. He could face the death penalty if convicted. He has pleaded not guilty. Nearly five years have passed since the shooting, but Mr Bowers' trial is only now kicking off in earnest. The trial began on Tuesday and is expected to last until late July. In the months leading up the shooting, Mr Bowers was allegedly spewing bigoted and antisemitic vitriol online, investigators say. He allegedly called immigrants "invaders" and posted racist memes, including some that accused Jewish people of being the "enemy of white people." On the day of the shooting he reportedly posted a message to a web forum, saying "I can't stand by and watch my people get slaughtered. Screw your optics, I'm going in." He then allegedly proceeded to murder 11 people at the synagogue. After his arrest, police learned that Mr Bowers had 21 weapons registered to his name. He was otherwise unknown to law enforcement. They then began to review Mr Bowers' online presence, finding an account on Gab — a supposedly free speech oriented, right wing social media alternative to the likes of Twitter — where he allegedly posted a steady slew of hate. His bio included the phrase "Jews are the children of Satan" and his posts consisted of anti-Jewish slurs and conspiracy theories, according to the New York Times. The conspiracy theories included allegations that Jewish people were smuggling Muslims into the US, and another showing an image of the Auschwitz concentration camp, with the photo doctored to make its infamous gate read "Lies Make Money." Days before the shooting he called then-president Donald Trump a "globalist" — often a term carrying antisemitic implications — and said "there is no #MAGA as long as there is a k*** infestation." The omitted word is a racial slur used against Jewish people. Police claim that after being shot and wounded at the synagogue, Mr Bowers said: “These people are committing genocide on my people. I just want to kill Jews.” His defence attempted to have that quotation barred from consideration at his trial, arguing he made the statement before he was read his Miranda warning. A judge denied the motion. The alleged gunman worked as a trucker before the shooting. Prosecutors are arguing that hate drove Mr Bowers' alleged attack on the synagogue. “The depths of the defendant’s malice and hate can only be proven in the broken bodies” of those killed, and through “his hateful words,” Assistant US Attorney Soo C Song said during her opening statement. Prosecutors claimed in an earlier filing that Mr Bowers allegedly “harbored deep, murderous animosity towards all Jewish people.” The defence — after unsuccessfully arguing against the use of Mr Bowers' statements to police and for a change of venue — have filed a notice of mental infirmity again his potential sentencing, according to court records. They claim Mr Bowers has been diagnosed with schizophrenia and epilepsy. His attorneys have also offered a plea deal in exchange for the removal of the death penalty. Read More Gab: Inside the social network where alleged Pittsburgh synagogue shooter posted final message Synagogue shooter 'listened to noise and noise told him his people were being slaughtered', says Jewish doctor who spoke to Robert Bowers Trial for accused gunman in Pittsburgh synagogue massacre slated to start