Ross Rubin's friend Eric Johnson was accidentally shot and killed at a DART light rail station in Richardson. A DART police officer was wounded in the same incident.
Two weeks later, Rubin says transit system security is still being ignored.
"Nothing has changed, and it's almost like Eric has been forgotten," he said.
DART says it's trying to improve.
"You've seen more officers on our trains, maybe in the last month, than you have in the history of DART," spokesman Mark Ball said.
DART passenger Brandon Baker is not so sure. He rides into downtown Dallas from the Parker Road Station in Plano to work at WFAA every day. Since the Richardson shooting, he's secured a handgun license.
"I don't have a handgun as of now," Baker said, "but it is something I'm looking into getting, and it is because of the recent shootings."
The root of security concerns for Baker and other DART riders News 8 talked to is passengers who board trains without buying tickets. DART says that amounts to only five percent of its riders, the lowest in the nation.
But riding free on DART is easy, because it operates on an honor system. There are no turnstiles; passengers buy tickets from vending machines on the platform.
Regular riders say the free-riders often board the trains only to cause trouble. Often, riders say, they confront DART fare enforcement personnel who ask for their tickets.
"It's not unusual to see it, because they do it all day, every day," said passenger Aaron Jackson.
DART says it doesn't have enough police to put an officer on every train, but it is trying to place uniformed officers on platforms, where they can be seen.
"We're approaching individuals, talking to them, asking them, 'What's your business on DART?'" Ball explained.
The configuration of DART trains is itself a problem. There are no connecting doors between cars. If fare cheaters spot a police officer on one car, they can move to another where the officer can't reach them.
Viett Miller and her son Corey are happy DART customers. "Me and my son ride DART quite often, and it's been wonderful," she said.
But she is armed with a can of pepper spray — just for safety's sake.
Signs aboard trains advise passengers what to do if they spot trouble. Within the next 60 days, DART said it will have a system in place where a passenger nervous about being spotted calling 911 can instead send a text alert to 41-411.
DART says its ridership has not decreased over the last month in the wake of recent violence. But passenger Aaron Jackson has an other perspective.
"You see all types of stuff on the train," he said. "It's an adventure every day."