What is the burden of proof at a revocation hearing for a probation violation?

Apart from the notice issue, substantial evidence did not support the probation violation, which required the People to prove, by a preponderance of the evidence, that appellant fired a gun at a shooting range within the probationary period. (People v. Rodriguez (1990) 51 Cal.3d 437, 447 [burden of proof at probation revocation hearing is preponderance of the evidence].) As noted, appellant was not placed on probation until January 9, 2012. The only evidence supporting the probation violation was his statement, on January 31, 2013, that he had fired a gun at a shooting range "a year, year and a half ago." Taken literally, this means appellant visited the shooting range sometime between July 31, 2011, and January 31, 2012. Only 22 days of this six-month period in which the shooting range incident might have occurred actually fall within the probationary period.⁵