Does a prior conviction of battery upon a police officer constitute moral turpitude?

Defendant testified, and the prosecution used a prior conviction of battery upon a police officer ( 243, subd. (c)), among other felonies, to impeach him. The trial judge ruled the prior conviction of battery upon a police officer involves moral turpitude. Defendant urges that battery upon a police officer does not involve moral turpitude within the meaning of the seminal case of People v. Castro (1985) 38 Cal.3d 301, 211 Cal.Rptr. 719, 696 P.2d 111.