Corporate jet Captain reported an NMAC with a light training aircraft on a visual approach to APA.

Narrative

On a visual approach to runway 17L at APA; I was told to look for an aircraft that was on base to the parallel runway. My co-pilot and I were doing final checks before landing. I was monitoring the electronic glide path and MFD for traffic. Speed was tracking to REF after final flap setting. The training aircraft on base was never seen but was displayed on the MFD. The two runways at APA are very close and the conflicting traffic was expected to be close. TCAS displayed the RA with verbal command to climb. At that time the MFD did show the traffic at our 12 o'clock and lower. RA climb procedure was begun with successful escape. This is not the first or even fifth time this has happened at this airport. Low time students training very close to arriving jet aircraft WILL result in ANOTHER midair collision. Before I have reported this same type of event; and suggested that traffic for the parallel runway not turn base until passing the traffic on final. I hope I do not have to report this again but I likely will; as long as I'm not the one who is killed in the midair collision that will happen there.