In more than 100 interviews with police, government officials, residents, and tourists who witnessed the week’s events, Globe reporters sought to reconstruct the actions of law enforcement agents between the April 15 bombing that killed three people on Boylston Street and the capture of Dzhokhar Tsarnaev seven miles away in Watertown on April 19 after his brother Tamerlan was killed, the conclusion of an epic 102-hour manhunt that left one police officer dead and another badly injured. The newspaper inquiry turned up scores of new details, fleshed out the hard questions law enforcement confronted along the way, and the harder decisions it was forced to make. It also helped put many previously reported elements in proper order and context. A maelstrom of information — some factual, some speculative, some flat out wrong — followed in the wake of the calamity, as it always does in times of tumult. This story aims to assemble what is known, and remains to be seen, in one consecutive account.