Napa Police were called to Napa Valley Expo at 7:35 a.m. Friday on a report of an unwanted male at the Winter Shelter.
Officers located the man in a field on the west side of the Expo where he brandished a knife at officers and threatened to harm both the officers and a police K-9, police reported.
When the man, identified as Jeffrey Dwayne Scott, 50, of Napa wouldn't submit to arrest, police backed off, closed off Burnell Street and evacuated a nearby business and tried to de-escalate the situation and negotiate with him.
Police said Scott was wanted on a felony assault with a deadly weapon warrant and was on active Post Release Community Supervision with terms that prohibited him from possessing a weapon.
Police ended the standoff at 11 a.m. using "less lethal kinetic projectiles" and a K-9 who bit Scott, said Lt. Brian Campagna.
Scott was taken to a local facility for medical treatment, Campagna said.
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