But in memory of all you served their country and didn't come back, here's a list of Mysteries set during Memorial Day Weekend (and a few others). Here's an updated list. Let me know if I've forgotten any titles. You may also want to check out my Veterans Day Mystery List.
Memorial Day Mysteries
Memorial Day by Vince Flynn
The Decoration Memorial Day War by David H. Brown
Absolute Certainty by Rose Connors
One Was a Soldier by Julia Spencer Fleming (not technically Memorial day, but it fits the theme)
Memorial Day by Harry Shannon
Beside Still Waters by Debbie Viguie
Shadows at the Fair by Lea Wait
The Memorial Day Mystery short stories on the web.
For the young set: The Mystery of the Memorial Day Fire by Kathryn Kenny, a Trixie Belden mystery.
Have a good holiday. Be safe and Remember.