Brian Gerard "Kato" Kaelin is an American actor and radio and television personality, who was a witness in the O. J. Simpson murder case.

The People of the State of California v. Orenthal James Simpson was a criminal trial in Los Angeles County Superior Court, in which former National Football League (NFL) player and actor O. J. Simpson was tried and acquitted for the murders of his ex-wife Nicole Brown Simpson and her friend Ronald Goldman. The two were stabbed to death outside Brown's condominium in the Brentwood neighborhood of Los Angeles on June 12, 1994. The murder trial spanned eight months, from January 24 to October 3, 1995.