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.

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 wasn'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.

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.

Read the rest of the Story