Police confirmed Wednesday that ex-NFL star Steve McNair's 20-year-old girlfriend killed him before turning the gun on herself.They said they may never know what was going through Sahel Kazemi's mind when she shot McNair in his condominium early Saturday, but interviews with friends led detectives to conclude she was becoming increasingly distraught over events in her life, including financial problems. Police said she also suspected McNair was seeing another woman. Police earlier had labeled McNair's death a homicide, but awaited further tests and investigation before saying for sure what happened. At one point, Kazemi told an associate that her...