Not enough evidence for arrest so far in Jewish protester death: Police

Authorities from the Ventura County Sheriff’s Office said Thursday night they currently do not have enough evidence to make an arrest in the death of a Jewish protester in Southern California.

Paul Kessler, 69, died early Monday morning from blunt-force head trauma following a Sunday confrontation with a counterprotester in Thousand Oaks, California, according to authorities. His death was ruled a homicide by the medical examiner.

In a lengthy statement released Thursday evening, the sheriff's office said the findings of the autopsy have been "misinterpreted by many.”

Homicide means Kessler's death was caused at the hands of another but "does not provide sufficient evidence to establish probable cause for an immediate arrest of a suspect," the sheriff's office said in a release.

Investigators have photos and videos from before and after the incident, in which Kessler fell backward and hit his head, authorities said. However, the sheriff’s office said it does not have any footage of the actual incident taking place, "which would be extremely helpful in this case and would undoubtedly show or could even refute criminal culpability,” the release read.

Eyewitness statements from those present when the altercation took place conflict with one another, the sheriff's department said, making it difficult for the authorities to prove the suspect's guilt beyond a reasonable doubt.

Multiple people called 911 to report an incident of battery on Sunday afternoon, including the person authorities have called the suspect in the incident -- a 50-year-old Moorpark resident who was attending the pro-Palestinian demonstration -- Ventura County Sheriff Jim Fryhoff said Tuesday.

Fryhoff said the suspect remained at the scene and was interviewed.

"Our investigators are working around the clock to track down leads, scrutinize electronic data, and corroborate witness statements," the sheriff's office said.

ABC News' Alex Stone contributed to this report.