confound

The final riddle confounded even the most experienced puzzle solvers.

Investigators were confounded by the missing evidence, since none of the security footage matched the witness accounts.

“Some combinations confounded senior epidemiologists because nearly identical starting points produced sharply different peaks.”
— from the passage When the Curve Breaks

“Their claims about guilt and forgiveness sound like slogans, while their cryptic gestures confound even attentive viewers.”
— from the passage The Engineered Tempest

“Riots erupted in several cities, and news from Bristol, where buildings burned and prisoners escaped, confounded politicians who had expected orderly petitions rather than urban violence.”
— from the passage The Reform Standoff