SIN, Having read the background on your character, I'm having a real hard time seeing how he'd be involved with a task force investigating violent crimes, other then as a suspect or target. Even as an informant, they wouldn't touch anybody who is habitually doing violent crimes or dirty work on behalf of anybody, no matter how useful their info might be. This group isn't operating outside or above the law, they are primarily embodied to pool local, state, and federal resources, and get around things like bureaucratic turf wars and jurisdictional issues.
Any chance you could tone down his background just a bit? A mass murderer just isn't what we need for this.