Police labeled the death an accident and said Capponi did not see his son while backing up into his driveway.
"Please forgive me and my family....I love him with all my heart...it is now broken," Capponi wrote in a message on his Facebook page.
Well-wishers and grieving friends posted their condolences to Facebook.
"No words can take away how you must be feeling. Just know that you and your family are in our thoughts and prayers. If you need anything just let us know," wrote one.
"I pray for you and your family. if you just need someone to talk to im right down the road," wrote another.