Did Fusco kill BOTH those cops? I thought he only got one of them, and then it was self-defense or defending John. Help on reminding me?
John killed the first cop in the pilot (John still uses his badge and name when he's pretending to be a cop) and the second cop (from internal affairs) was gonna kill Fusco before John killed him. So I'm not sure why Fusco just doesn't fess up to Carter that they were both dirty HR cops that John killed.
Though Fusco did kill the HR police captain who was gonna kill John.
For the HR angle, Simmons thinks Fusco killed the internal affairs cop and needed HR's help covering it up. That was his way back into HR.