A man involved in a confrontation at Portland International Raceway Thursday has died from his injuries, Portland police say.

Police identified him Friday night as 61-year-old Anthony Mancuso.

Officers were called to the raceway at 8:17 p.m. Thursday after reports that the families of two motocross riders were fighting. Michael Taylor was arrested that night on allegations of fourth-degree assault, but those charges were dismissed Friday pending a grand jury.

Taylor told county court officials that he was defending his son, a motocross rider, from bullying by another rider and his father.

Police offered no further information on Mancuso, including his role in the altercation and relationship to those involved.

Detectives Mark Slater and Erik Kammerer have been assigned to the investigation. They're requesting that anyone who witnessed the assault or might have video of the incident to contact them.

Slater can be reached at 503-823-9319 or mark.slater@portlandoregon.gov, and Kammerer can be reached at 503-823-0762 or erik.kammerer@portlandoregon.gov.

-- Melissa Binder

mbinder@oregonian.com

503-294-7656

@binderpdx