Why are we supposed to be feeling concerned about this? Epileptics die from fits quite frequently. Are you trying to imply that the polive are in some way responsible for his death?
He committed a crime, or crimes thought serious enough to need to ambush him in the middle of the night to secure an arrest. His fit may, or may not have been brought on through the stress of the arrest - who can know for sure? Plenty of people have very bad fits resulting in death or injury for no reason whatsoever.
He died as a result of the fit. Not as a result of police brutality. It will nreed to be investigated, obviously, but just because there is an investigation it does not follow that the police were in any way at fault.
The police were not to know he was epileptic, and even if they did, what do you expect them to do? Not arrest him, just in case? 
Anyone can drop dead of a heart attack at any time while being arrested. We still do need to go ahead and arrest suspected criminals though - in spite of that very small risk.