Suspect Jamal Jackson, 49, was arrested shortly after the attack in Ventura and charged with intentional murder, District Attorney General Ventura said.
Mele died the next day, but his daughter was not injured. The two men did not know each other, said the Ventura Police Department.
Hours before the attack, a 911 viewer called to report Jackson "roars" and other disturbing behavior on a boardwalk in Ventura, police said. The authorities said they found it was not a threat and canceled the call to serve.
There were no officers available to monitor him immediately, and the police began monitoring him with security cameras from the control center, the Ventura police department said Saturday.
"At the time of the call, patrol resources in the area were assigned to other service calls," the police said.
About three hours later, Jackson stabbed Mele on the neck as he dined at the Aloha Steakhouse – a beachside restaurant across the boardwalk where Jackson was seen, police said.
Mele was operated on, but eventually removed from the hospital Thursday, police said
spectators pursue suspects
Jackson was arrested after a group of passers-by had chased him to the beach. He was initially charged with attempted murder and child molestation, the police department of Ventura said.
His motive is still unclear, officials said.
If convicted, he will be punished with 55 years imprisonment. Information about his lawyer was not immediately available.
Janet DiGiacomo of CNN contributed to this report.