Complex sentence: Tom arrives and confronts them, and while he argues with Anna, Rachel steals a corkscrew and steps outside to call the police, but Tom catches up to her and attempts to strangle her as Anna watches from the window.
Split into simpler sentences: Tom arrives and confronts them, and while he argues with Anna, Rachel steals a corkscrew and steps outside to call the police. However, Tom catches up to her and attempts to strangle her, as Anna watches from the window.