In addition to the RTD Transit Police, who are stretched thin because of short staffing, TSA officers will be patrolling not just the underground terminal but the platform up above.

The shooting happened at about 10 p.m. Monday and shut down the terminal for several hours during the police investigation, RTD spokeswoman Tina Jaquez said.

To that end, RTD is modernizing its fare-collection system by moving to account-based ticketing. “RTD still has ticket vending machines, which is the antiquated form of technology,” Johnson said.

Denver Union Station, the jewel in RTD's crown, is tarnished and RTD is not taking sufficient action to keep us all safe," said the ATU. RTD spokesperson Pauline Haberman told CBS4 the agency is ...