Jessica

Warning – Reading on may contain spoilers if you have not yet solved the murder.

The discarded list appears to be an attempt to determine who the saboteur is. The person who made the list seems to have worked this out.
What is interesting is that the list does not include Mike or Jessica. However, the logo for Mike’s business from his business card is on the sheet, so he is represented, just for another reason. Thus, only Jessica is not listed. Given that you don’t need to put yourself on a list of suspects since you know aren’t the one, Jessica is the most likely person to have made the list.
Jessica came in 4th place. However, if she knew something about both Mike (2nd place) and Maud (3rd place) that would disqualify them, then only Justin (1st place) is in her way to receive the $1 Million Dollar Prize. In such as a case, Jessica would have a Motive to kill Justin, quite a lucrative one. Because the murder weapon is a taser that anyone could have possessed and used, she also means. What’s missing for Jessica is Opportunity.
The running app seems to give Jessica an airtight alibi. However, upon closer examination, there is an interesting fact that arises.

Even More about the Running App:
Upon taking a closer look at the running app, Jessica’s route is in two loops that are about the same length. Her total route was 13.16 miles, so each loop was about 6.5 miles, give or take. From the route shown on the app, the first loop starts at 11:12 and ends at 11:33 for a total of 21 minutes. This means the first loop of 6.5 miles was completed in 21 minutes or at a pace of 3.23 minutes per mile!

It’s unbelievable that a psychologist could run a faster mile than an extreme runner like Justin by more than two minutes! (A quick Internet search shows that the current world record for running the mile is 3 minutes 43 seconds.)

The key realization is that the app tracks the phone’s position, not Jessica’s.

Jessica could have started the running app and left her phone in a cab just before the murder. Minutes after completing the murder, Jessica could have called her phone. The cab driver would hear it ring and pick it up. Jessica would ask the driver to return her phone a block away from the hotel. Once she got her phone back, she would walk slowly through the second loop until she got her average time per mile up to a more realistic number (7:31).

Why Jessica would be disqualified:
According to Rule 6, any contestant ‘committing a felony-class offense before the prize is awarded’ will be disqualified. When you demonstrate that Jessica is the murderer, she is quickly disqualified.