LA Sheriff Refuses to Enforce New Mask Mandate: 'Not Backed by Science' On 7/17/21 at 8:44 PM EDT Alex Villanueva, the Los Angeles County Sheriff who has been called "the Donald Trump of L.A. County," has said that his office will not enforce the county's recently re-instated mask mandate. Villanueva says the mandate is "not backed by science." The county's indoor mask mandate went back into effect on Saturday by order of the Los Angeles County Department of Public Health (DPH). The DPH cited rising COVID-19 case numbers as the reason for reinstating the mandate. The mandate requires all people to wear masks indoors, regardless of vaccination status.