Family of Black Man Found Hanging From Tree Dispute Suicide Finding

City officials in Palmdale, Calif., said on Saturday that they support calls by activists and residents who have demanded an independent investigation into the death of a 24-year-old black man who was found hanging from a tree in a public square this week.

The death of the man, Robert L. Fuller, which officials initially deemed a suicide, has deeply shaken the city in northern Los Angeles County and has reverberated far beyond amid nationwide protests against racism that were set off by the death of George Floyd.

At a rally for Mr. Fuller on Saturday, his sister, Diamond Alexander, said that the initial determination by officials that her brother hanged himself did not make sense.

“Everything that they’ve been telling us has not been right,” she said, according to video of the rally in Palmdale. “We’ve been hearing one thing. Then we hear another. And we just want to know the truth.”

She added: “My brother was not suicidal. He wasn’t.”

Hundreds of people marched and held signs that read, “Justice for Robert Fuller” and “Black Lives Matter.” Protesters called out: “Say his name!” and the crowd chanted, “Robert Fuller.”

A passer-by found Mr. Fuller’s body hanging from a tree in Poncitlán Square, across from Palmdale City Hall, at around 3:39 a.m. on Wednesday, according to the Los Angeles County Sheriff’s Department.

Personnel from a nearby fire station responded and determined that Mr. Fuller was dead, the department said. The Los Angeles County Sheriff’s Homicide Bureau and the Los Angeles County Coroner’s Office also responded.

“Although the investigation is ongoing, it appears Mr. Fuller, tragically, committed suicide,” the Sheriff’s Department said in a statement on Friday, adding that a full autopsy was expected soon.

The city of Palmdale said in a statement on Saturday that it was “officially supporting the call for an independent investigation and an independent autopsy” of Mr. Fuller.

“The City of Palmdale is joining the family and the community’s call for justice, and we do support a full investigation into his death,” the statement said. “We will settle for nothing less than a thorough accounting of this matter.”

Deputy Sheriff Eric Ortiz, a department spokesman, said on Saturday that the agency had no immediate response to the call by city officials and activists for an independent investigation. He said the Homicide Bureau was continuing to investigate. The county coroner’s office did not immediately respond to messages on Saturday.

After officials released their account of Mr. Fuller’s death this week, it was immediately challenged by activists, residents and people on social media.

At a news conference called by officials at Palmdale City Hall on Friday, residents said they had no faith in the local authorities to properly investigate Mr. Fuller’s death and wanted complete transparency and an independent review.

“Why was it right here in public, in front of City Hall, next to a church, in front of a library?” one woman said. “Why was it like that? Who would do that? No black man would hang himself in public like that.”

Others demanded to know if there were video cameras in the area and to know who found Mr. Fuller.

The Palmdale city manager, J.J. Murphy, said that the city was working with the authorities to identify footage from cameras around the area. There are no city cameras in the park, he said.

Some said the authorities had rushed to judgment without gathering all of the facts.

“That’s a lie!” several people shouted after Capt. Ronald Shaffer of the Sheriff’s Department said it appeared that Mr. Fuller died by suicide.

“Can I also ask that we stop talking about lynchings?” Mr. Murphy said at another point during the news conference, prompting people in attendance to respond, “Hell no!”

Kim Kardashian West, the reality TV star, weighed in on Twitter on Friday, urging her more than 65 million followers to sign a petition to demand a thorough investigation.

“This was not a case of suicide but murder,” reads the petition.

The N.A.A.C.P.’s Antelope Valley branch said in a statement that law enforcement needed to provide answers.

“A grieving family deserves to know if foul play was involved,” the statement said.

Mayor R. Rex Parris of Lancaster, a nearby city, said law enforcement officials told him on Friday that all signs pointed to a suicide, and that there were no signs indicating any other cause of death.

“There were apparently scars on his body consistent with previous attempts,” Mr. Parris said.

In a Facebook post on Thursday, Ms. Alexander included a link to a local news story about the body found hanging from a tree.

“Words can’t describe how much my family is hurting right now,” she said in a separate post on Thursday. Ms. Alexander asked for the public’s help, urging anyone who had seen anything to “please come forward.”