Complex sentence: On one of his trips to Setauket, Brewster was waiting for Woodhull in Anna Strong's back garden where he surprised a passing British lieutenant, pulled him off his horse, and had the opportunity to capture or kill him.
Split into simpler sentences: On one of his trips to Setauket, Brewster was waiting for Woodhull in Anna Strong's back garden. While waiting, he surprised a passing British lieutenant, pulled him off his horse and had the opportunity to capture or kill him.