Question: who did mike kill in better call saul

title: Five-O (Better Call Saul)
text: In another flashback , Mike is seen breaking into a police car parked outside a bar . He enters the bar , and after a few drinks , confronts Fenske and Hoffman , telling them `` I know it was you '' . A few hours later , as Mike is the last customer and the bar is about to close , he announces to the barkeeper that he plans to move to Albuquerque and leaves . As he staggers home , Fenske and Hoffman drive up in their patrol car , offer him a safe ride home , and seat him in the back seat . They take away his handgun and ask him what he meant earlier in the bar . Mike , apparently still drunk , slurs that he knows that it was them who killed Matty . As the two drive Mike to an abandoned factory site , he retrieves a hidden gun from the backseat cushions . When it becomes clear that Hoffman and Fenske intend to kill Mike , he reveals that his drunken stupor was faked . Fenske attempts to fire at Mike , but discovers the gun he took from Mike is empty . Mike promptly shoots Fenske three times in the chest . Hoffman tries to pull out his gun , but Mike quickly dispatches him with a bullet to the head . Fenske is able to draw his duty - issue pistol and fires off two rounds , one of which strikes Mike in the left shoulder . Mike returns fire , hitting Fenske in the neck . Though mortally wounded , Fenske tries to crawl away . Mike slowly walks towards him and steps on his leg , preventing him from reaching for his weapon again . Fenske raises his other hand as if to beg for his life , but an unmerciful Mike finishes him off by shooting him in the head . Mike collects his gun from Fenske and walks off , preparing to depart for Albuquerque . 

Answer: answer: Hoffman tries to pull out his gun, but Mike quickly shoots him with a bullet to the head.  Fenske raises his other hand as if to beg for his life, but an unmerciful Mike finishes him off by shooting him in the head.