Diagram of Boylston Street showing the finish line, photo bridge and Boston Public Library

The diagram presents Boylston Street from above, including the finish line, photo bridge, and older and newer portions of the Boston Public Library. Thomas Grilk said it appeared to scale based on his street familiarity, but acknowledged taking no measurements and could not verify every depicted business's presence in 2013 or identify certain brown features. The court permitted its use while reserving admission, and it remained a chalk rather than admitted evidence during Michelle Gamble's Day 51 testimony.