( CNN ) -- A Pennsylvania man who walked into a gym aerobics class and opened fire , killing three women and wounding nine before turning the gun on himself , `` had a lot of hatred in him , '' police said Wednesday . Pregnant aerobics instructor Mary Primis was teaching class when the gunman opened fire , critically injuring her . George Sodini , 48 , brought four handguns into the LA Fitness gym outside Pittsburgh and used three of them , firing at least 36 times around 8 p.m. Tuesday , Allegheny County Police Superintendent Charles Moffatt said . Sodini , a member of the gym , was found dead in the aerobics room , lying on top of one of his guns about seven feet from one of the victims . Authorities believe Sodini targeted the aerobics class , because a schedule was found in his home with that class circled , Moffatt said . But police do not believe he targeted anyone personally . An online diary , as well as notes at the scene and at his home , have led them to believe he was targeting women in general . Read an edited version of the diary ( PDF ) In the note found at the scene in Sodini 's gym bag , he complains he had never spent a weekend with a woman , never vacationed with a woman and never lived with a woman , and that he had had limited sexual experiences , Moffatt said . He makes similar complaints in his online blog , which also documents his growing rage at women for rejecting him and at the world he felt had abandoned him . Witnesses told police the gunman was dressed in black when he entered the class , shut off the lights , walked about 10 feet and opened fire . Mary Primis , 26 , an aerobics instructor who is 10 weeks pregnant , was shot twice . `` I remember thinking I wanted to hold my breath because I was afraid , if he saw that I was breathing , he would shoot again , '' she told CNN affiliate WPXI from her hospital bed . Asked if she thought she was going to die , she said , `` I was n't sure . '' Her husband , Alex Primis , said she was shot once in the left shoulder and again through the back of her shoulder blade . This was to be her last week teaching before taking time off for her pregnancy , Primis said . Sodini apparently had `` practice runs '' before the shooting Tuesday , Moffatt said . Someone at the gym had showed him how to shut off the lights , he said , not knowing his plans . `` He just had a lot of hatred in him , and he was hell bent on committing this act , '' Moffatt said . Watch Moffatt describe contents of diary » . Sodini worked as a systems analyst in the finance department of K & L Gates , a law firm with an office in Pittsburgh , since 1999 , Mike Rick , a spokesman for the firm , said . Neighbors described him as reclusive and said he had stopped talking to them in the past few years . On Tuesday , Sodini visited the gym three times -- the first about 11 a.m. , a second time at 7:40 p.m. and a third time at 7:56 p.m. , Moffatt said . Members of the gym are required to swipe a card to check in , but do not have to check out , he said . The first 911 call was dispatched at 8:16 p.m. Three of the four guns found with Sodini were traced back to him , and authorities are in the process of tracing the fourth , Moffatt said . They were two 9 mm semi-automatics , a .45-caliber revolver and a .38 in his pocket . Sodini also had 30-round ammunition clips that were illegal before the assault weapons ban was lifted in 2004 , police said . Police know Sodini made a telephone call at 7:45 p.m. , and believe he may have left the gym to make it . Authorities are attempting to locate the person he contacted , Moffatt said . Sodini did not mention killing himself in the note found at the scene , which was mostly typed with handwritten notations , but did mention it in a handwritten note found at his home , Moffatt said . Police seized Sodini 's car for processing , but no guns were found in it , he said . They also seized his computer and were examining it . The shooting victims were taken to the three major hospitals in the area . Moffatt said he believed none of those who remained hospitalized Wednesday had life-threatening injuries . County officials said counselors were being made available to area residents in the wake of the shooting . Police spoke to a pastor mentioned on Sodini 's online diary . The man said Sodini attended his church but stopped in 2006 , and that there was a minor incident involving a woman who felt `` he was paying too much attention to her , '' Moffatt said . The pastor spoke to Sodini , and it stopped , he said . Moffatt said police have no knowledge of any mental health issues involving Sodini , but are still puzzled at the violence . `` I ca n't ever make sense of murders , '' he said . CNN 's Susan Candiotti contributed to this report .
NEW : Police find gym schedule with class circled in gunman 's home . NEW : Notes , diary indicate gym shooter was targeting women in general . Gym member George Sodini , 48 , talks about his hatred of women in note . Shooting at LA Fitness leaves three women and shooter dead , police say .