LOS ANGELES — A college professor was arrested Thursday in connection with the death of a Jewish protester during Southern California demonstrations over the Israel-Hamas war, authorities said.

Details of the Arrest

Loay Abdelfattah Alnaji, 50, will be booked into jail for investigation of involuntary manslaughter — the unintentional killing of another person, the Ventura County Sheriff’s Office said. The district attorney will decide whether there is enough evidence to charge him.

A man who answered the phone at a mobile number listed for Alnaji in public records said he did not want to comment. He did not give his name. A message could not be left at a number for Alnaji’s home in Moorpark north of Los Angeles, because voicemail was not set up.

The Incident

Paul Kessler, 69, died early Nov. 6 at a hospital following a Nov. 5 confrontation with a pro-Palestinian demonstrator in Thousand Oaks, a suburb northwest of Los Angeles.

Sheriff Jim Fryhoff said at a subsequent press conference that deputies determined Kessler fell backward and struck his head on the ground. The pro-Palestinian demonstrator stayed at the scene and told deputies he had called 911, Fryhoff said.

County Medical Examiner Dr. Christopher Young said at the time that an autopsy found Kessler died from head injuries consistent with a fall. Young also said Kessler had injuries that could be consistent with a blow to the face but that it was unclear what caused his fall.

Investigation and Arrest

Kessler’s death was ruled a homicide, but authorities said that only meant his death was caused at the hands of another and by itself was not sufficient evidence to establish probable cause for an immediate arrest of a suspect.

Authorities did not say in Thursday’s news release why an arrest was warranted. They said they were still seeking more video evidence in the case. A short video clip surfaced showing Kessler on the ground, but there haven’t been any videos released showing the actual confrontation.

In a news conference days after Kessler’s death, Fryhoff said authorities briefly detained a 50-year-old man from Moorpark and searched his home, but he was then released.

The Sheriff’s Office has said investigators received conflicting information from witnesses on both sides about what took place, impairing witness credibility and making it difficult to prove a case beyond a reasonable doubt.

The Demonstration

Kessler was among a group of pro-Israel demonstrators who showed up at the event that was advertised as a peaceful gathering to support Palestinians. About 75 people in total were there and patrols in the area reported seeing no indication of violence 15 minutes before the altercation, officials said.

Demonstrations have been widespread and tensions are escalating in the United States as the death toll rises in the Israel-Hamas war.

Community Response

The Jewish Federation of Greater Los Angeles said in a statement that it was grateful for the work of sheriff’s investigators.

“This arrest shows that violence towards our Jewish community will not be tolerated,” the federation said.