According to the LML archives link to Mr. Rogers website, Mr Rogers built a Walter turbine IV-P tail number N724HP.
Another paper indicated that the plane kept circling the airport with a landing gear issue and ran out of fuel. However there was a post crash fire, so I am not sure what is accurate
The story indicated that both the pilot and the younger passenger were on their cell phones with their wives. What a tragedy. I feel for their families.