Houston police said the man the attempted robber targeted is a military veteran.
The shooting happened in the 1900 block of Main Street near Pierce Street around 8:48 p.m. Monday.
Police said the veteran was waiting to catch a ride home on the METRO when a would-be robber picked the wrong person to mess with.
The man told HPD the 18-year-old suspect ran up to his wheelchair and tried to take his backpack, but he had a handgun and put up a fight the suspect likely never saw coming.
"He fired multiple shots, striking the suspect," Lt. J.P. Horelica said. "The suspect ran several hundred yards, where he collapsed and was picked up by the Houston Fire Department and treated."
Police said the would-be robber had multiple gunshot wounds. He was taken to the hospital in serious but stable conditon and is expected to survive.
Once the 18-year-old is well enough to speak with investigators, police expect charges to be filed.
For more on this story, follow Jeff Ehling on Facebook, Twitter and Instagram.