Garrus tells Shepard that, a few years ago, he was assigned to investigate black market trading on the Citadel, and found there was an increase in the sale of body parts. C-Sec was unsure whether it was a lab selling organs illegally, or if a psychopath was dismembering people, yet the situation turned out to be more complex than this. Garrus ran a DNA check on a recovered turian liver, only to find the supposed donor was very much alive. He later found that this turian had worked for Dr. Saleon. Garrus inspected Saleon's lab, but there was no sign of any cloned body parts nor the machinery to grow them — "no salarian hearts, no turian livers, not one krogan testicle".
Running out of ideas, Garrus brought in some of Saleon's employees for a "chat". During the interrogation, one interviewee began bleeding and the C-Sec medics found that he had fresh incisions all over his body. It turned out that Saleon was using his employees — who were usually poor and desperate — as living test tubes: cloning their organs, growing them inside their own bodies, then removing and selling them, giving his employees a small percentage of the profits. If the organs failed to grow properly, Saleon would simply leave them inside the body, with dire consequences for the employees' health.
C-Sec went to arrest Saleon, but, knowing his operation had been discovered, Saleon destroyed his lab, snatched some of his employees and fled the Citadel on his ship. Garrus wanted the Citadel defence forces to shoot Saleon down, but C-Sec overrode his order since the vessel was too close to the station, and Saleon escaped. The doctor later changed his name to 'Dr R. Heart' — "his idea of a joke" — and switched ships, buying and equipping the MSV Fedele to continue his research. Garrus tells Shepard that he has the transponder codes for Saleon's ship. Shepard agrees to investigate it, and Garrus asks to be taken along.
When Shepard's team boards the MSV Fedele, the Commander finds test subjects resembling Thorian Creepers wandering the cargo bay. Dr. Saleon is found in one of the compartments at the back. If Garrus is in the party, he recognises the salarian, though Saleon pretends to be innocent. Shepard can allow Garrus to execute Saleon or convince him that it would be better to arrest the doctor. Even if Garrus is convinced, Saleon refuses to be taken in, and is killed in the ensuing firefight.