Born to a pair of Gangers in Mexico City who ascribed their allegiance to a small gang called the Los Caballeros Templarios they decided to 'give their son a better life' (and make a few bucks off it too) and gave him to Orbital Air (for a generous wellbeing package) to put him in a research study group.

Riot never found out where he had been housed, grew up and trained but he's had some guesses over the years.  He was a natural though when it came to the human body and it was almost less skill and more artform when it came to both the flesh and machine that people were incorporating seamlessly (or not so seamlessly) into their bodies.  When he finished his initial studies he chose to not take up Orbital Air on a position in their Medical Corps, despite them having some of the best well stocked operating theaters anywhere, and instead decided he wanted to get some 'real' experience under his belt.

A former student, upperclasswoman to him, took a role there teaching and he had her pestering him to do more and better his final year.  She wasn't ready to give up on recruiting him the same way her own mentor had scooped her up.  Much as she thought it was a mistake she helped set him up.  Her connections in the Mayor's Office slowly included him as well...never the Mayor or the direct inner circle...no those could change too easily.  She made sure she had the loop in on the ground level.  Workers who actually moved the paperwork and orders and wouldn't change with a regime change based on who was paying the salary of the newest Mayor.  They helped set him up doing some off-books work for people in the office as on-book work with the NCPD and specifically the Psycho Squad members since he wanted the hard ones to work his magic on.

From there he became making his own contacts after she had gone back to Orbital Air to the Research Facility.  His work was good, he kept his mouth shut and since he hadn't made a big name for himself was relatively cheap too.  That's how he met Killroy & Phoenix initially while later crossing paths with Artemis.  There were a few others that he recognized but hadn't made any strong inroads with them yet to where they trusted him with more than a one off scrape or repair...