Is a unanimous jury required in criminal cases?

The right to a unanimous jury in criminal cases is guaranteed by the California Constitution. (See People v. Russo (2001) 25 Cal.4th 1124, 1132, citing Cal. Const., art. I, 16 [which expressly states that "in a civil cause three-fourths of the jury may render a verdict," thereby implying that only a unanimous jury may render a verdict in a criminal cause]; see also People v. Jones (1990) 51 Cal.3d 294, 321 ["the requirement of unanimity in criminal cases is of constitutional origin"], also citing Cal. Const., art. I, 16).)