https://www.snopes.com/fact-check/iowa-man-16-years-lgbt-flag/
What's True
The act of setting fire to an LGBT rainbow flag in Ames, Iowa, in June 2019 did ultimately result in Adolfo Martinez receiving a total sentence of 16 years in prison.
What's False
Several news articles failed to mention that Martinez' sentence would not have been nearly so long if he had not already been convicted of two previous felonies and treated as an "habitual offender," in keeping with Iowa state law. In that circumstance, his criminal history tripled the maximum available sentence for arson from five years to 15 years.