Kohlhepp had traveled to Superbike Motorsports in Chesnee, South Carolina, and spoke with the shop owner and another employee.
"He wanted to learn how to ride a motorcycle and they laughed at him when he fell over on the bike," said Kohlhepp's mother, Regina Kohlhepp. "You know, this is all why people tell kids not to bully. This is what can happen."
"Todd was bullied and embarrassed and I think he just held it in long enough," his mother said Friday.
It's not clear whether the four died on the same day as the incident with Kohlhepp, or if he returned another time.