57-year-old Gary Breitling of Montana lost his life while riding an RTC bus Saturday.
The terrifying shooting that led to a tense barricade on the Las Vegas Strip is believed to have been caused by Rolando Cardenas. Police say his mental issues were "very evident" as they tried to negotiate during the standoff.
Officers say Cardenas didn't know Breitling or the other victim who was hurt.
"He was on the second floor at the rear of the bus, and he just started shooting indiscriminately," said Assistant Sheriff Tom Roberts from the Las Vegas Metropolitan Police Department.
The shooting happened just three months after another person was shot and killed while riding an RTC bus. Darryl Peters is a former bus driver for the RTC and says he often worried about violence breaking out on board.
"[Police] can't be everywhere all the time," he said. "They do come. They do respond. But by that time you have a tragedy. It's too late."
Peters thinks more security is necessary to protect the lives of bus drivers and ensure every passenger makes it to their destination unharmed.
"At the end of the day, they have a family and they want to go home too," Peters said. "This guy who lost his life yesterday... He ain't gonna be able to go home and it's sad. It's really sad."