Ocam's razor

"So let me get this straight" the prosecutor says to the defendant. "You came home from work early and found your wife in bed with a strange man".

"That's correct" says the defendant.

"Upon which" continues the prosecutor "you take out a pistol and shot your wife, killing her".

"That's correct" says the defendant.

"Then my question to you is - why did you shoot your wife and not her lover?" asked the prosecutor.

"It seemed easier" replied the defendant

Spoiler:

"than shooting a different man every day!"