The rates have been credited to several initiatives, particularly the agency's completed installation of security cameras on more than 800 rail cars, covering nearly every CTA train.
Surveillance has also been utilized heavily in rail stations.
"You have complete saturation, 23,000 cameras throughout the system, making sure that our riders have safe, reliable and secure rides on our public transportation system," Emanuel said.
The mayor's office said the drop in crime is also attributed to police presence on train lines in high-crime areas. Officers, both in-uniform and undercover, have been sent to patrol these lines, officials said.
Officials also claim that the cameras have also helped get some criminals off the streets.
"Our offenders now realize that we're using this as evidence against them," said Chicago Police Commander Nancy Lipman. "The cameras have become, really, our best witness to crimes. You can't deny what's on film."
The Guardian Angels, a volunteer patrol group that watches CTA routes, also credits the cameras for identifying suspects. Footage is being used to help identify a suspect that stabbed four Guardian Angels two years ago.
"That was instrumental, and that's actually going to be able to be used in court," said Miguel Fuentes, a member of the Guardian Angels.
Rider reviews are mixed, however, about whether these measures make them feel any safer on the CTA.
"It feels like at least if something happened, they would see it and be able to see who did it," said Lizzy Powers, a CTA rider.
"If you're riding the green line, the red line, it still gets a little dangerous," said Alonzo Lee, a CTA rider. "You just never know what to expect out there."
Many Lakeview residents also believe crime, especially at night, remains a big problem at the Belmont Red and Brown Line station.
"We just don't trust the statistics, we still don't believe we have enough police," said Chester Kropidlowski of East Lakeview Neighbors.
Chicago's statistics measure crime for the first three months of the year compared with the same period in 2013.