The woman was attacked at gunpoint at the Miller station at Highway 12 and Lake Street.
The 68-year-old woman was sitting inside the passenger shelter, according to the northern Indiana transit police. She was attacked Saturday around 11:45 p.m. Authorities say the incident was recorded by transit parking lot security cameras.
Police say the footage shows the man with a handgun fleeing east from the station on a dark-colored BMX-style bike.
The victim was taken to a hospital for treatment.
Commuters are disturbed by news of the crime.
"You don't see a lot of police patrols in the area. I have heard of people being attacked at McDonald's just up the street, but honestly, I'm not surprised to hear something like that would happen," said Milinda Morgan.
If anyone has any information on the crime, they are asked to call the transit police at 219-398-6000.