The acquittal of an undocumented Mexican immigrant in the shooting death of a woman on a San Francisco pier apparently came down to a question of reasonable doubt, according to experts in criminal prosecution.

The jurors were evidently not convinced that the defendant, Jose Ines Garcia Zarate, acted with intent — a bar prosecutors needed to clear to convict him of the most serious charges, NBC News reported.

“As controversial and tragic as this case may be, and as political as it has become, my best guess is that this turned out to be a very conventional case in that … the defense just cast doubt on the prosecution’s theory,” said Robert Weisberg, a criminal justice professor at Stanford Law School.