Hayden Panettiere's onetime boyfriend Brian Hickerson and his brother Zach Hickerson were at the scene when the actress died Sunday at an apartment complex in Greenville, South Carolina, according to a police incident report obtained by NBC News.

The heavily redacted report says the brothers were inside the Judson Mill Lofts complex when Panettiere, 36, went into cardiac arrest. Responding officer Matthew Bryan said he first spoke with Zach Hickerson, who was "very emotional" while emergency medical services worked on Panettiere. Brian Hickerson did not become visibly emotional until EMS declared her dead, the report states.

Brian Hickerson showed police a "bag of medication" that Panettiere was taking at the time of her death, according to the report. Officer Bryan said he was wearing a body camera throughout the emergency response; the video has not been publicly released. Both brothers did not respond to NBC News' requests for comment.

Death investigation underway

The Greenville County Coroner's Office said Panettiere's cause of death is pending further investigation. In a statement, officials confirmed an autopsy was completed Monday and "no signs of trauma were discovered that would have contributed to the death."

Authorities received a 911 call around 1:50 p.m. Sunday about a "reported cardiac arrest" at the apartment complex, according to the coroner's office. An acquaintance of Panettiere's made the call. Panettiere was found unresponsive inside the residence where she had been temporarily staying. First responders initiated cardiac life support measures, but resuscitation efforts were unsuccessful; she was pronounced dead at 2:32 p.m.

Us Weekly reported that dispatch audio indicated Panettiere may have suffered an "overdose" and then went into "cardiac arrest." The cause of death has not been publicly revealed.

Police were seen outside Brian Hickerson's family home three days after Panettiere's death. Two Greenville Police Department cars were spotted outside a property owned by his grandmother on Wednesday, August 19, in photos obtained by Page Six and reported by Us Weekly. An officer knocked on the front and side doors without reply. Greenville Police said in a press release that the welfare check call was "unrelated to the Hayden Panettiere death investigation and did not require an incident report."

Past relationship and legal history

Panettiere's relationship with Hickerson appeared to end in 2020 amid domestic violence allegations. In her memoir "This Is Me: A Reckoning," published three months before she died, Panettiere wrote that Hickerson beat her so badly she did not leave the house for weeks. Hickerson was arrested May 2, 2019, on an allegation of injuring a spouse or girlfriend. He pleaded no contest on April 20, 2021, and was sentenced to four years' probation. Panettiere requested a restraining order against him on July 14, 2020.

In a 2020 statement, Panettiere said she was going public about the abuse to inspire others in abusive relationships to seek help. Hickerson's criminal defense attorney did not respond to a request for comment.

Panettiere's father, Skip Panettiere, issued a statement to Us Weekly: "It is with profound sadness that we share the tragic passing of our beloved Hayden. She was an incredible light and a force of nature who brought immeasurable love and joy to all who knew her — and to the millions who watched her onscreen. We ask for privacy as our family takes time to process this unimaginable loss."

Hayden is survived by her parents and her 11-year-old daughter, Kaya, whom she shared with ex-boyfriend Wladimir Klitschko. Her younger brother, Jansen Panettiere, died in 2023 at age 28 from an undiagnosed heart condition.

Panettiere was best known for her television roles in NBC's "Heroes" and ABC's "Nashville."