If you found that the Hammer is innocent by finding the information on the back of the article, 'Popular child phycologist murdered' and applying the information to the map, then congrats! If you haven't, go back and check the information  on those two pieces and come back when you've figure dit out! The answer is at the bottom of this page...

You found the article about the Dale River Bridge being closed from 8:45 p.m. to 9:45 p.m. According to the map, the Hammer couldn't have gotten across the river to Tullys and back to Elsmere  Park in time. Now you may open up Bonus Envelope A!