Complex sentence: Although, by most accounts, there was a poor examination of circumstances; it was ruled an accidental death though foul play was suspected by some especially given Gray's possible association with reputed mob boss Meyer Lansky.
Split into simpler sentences: Although, by most accounts, there was a poor examination of circumstances, Gray's demise was ruled an accidental death. Foul play was suspected by some, especially given Gray's possible association with reputed mob boss Meyer Lansky.