The Denver district attorney has launched an investigation into how a spreadsheet of voting system passwords ended up on the Colorado secretary of state’s website earlier this year. The DA’s office on Monday would not divulge any additional details of the probe beyond confirming an open investigation. On Oct. 29, Secretary of State Jena Griswold announced that a spreadsheet posted publicly on her office’s website for several months “improperly included” a hidden tab that displayed passwords protecting Colorado voting machines in many counties.