New details have emerged in the investigation into the Death of Sen. Lindsey Graham after Washington, D.C., officials released preliminary findings from his autopsy Sunday.
According to Fox News, the Metropolitan Police Department and the District of Columbia's Office of the Chief Medical Examiner said Graham, 71, was pronounced dead at George Washington University Hospital at 10:23 p.m. Saturday.
Authorities confirmed that an autopsy was completed Sunday as investigators continue reviewing the circumstances surrounding his Death.
According to a joint statement, the Metropolitan Police Department is leading the investigation, while the Office of the Chief Medical Examiner is responsible for determining the official cause and manner of Death.
Officials also released the medical examiner's preliminary findings, which concluded that Graham suffered an aortic dissection caused by arteriosclerotic cardiovascular disease.
Even with those findings, authorities said the investigation is not complete.
The medical examiner's office noted that comprehensive toxicology testing and microscopic analysis are still pending, describing those procedures as standard parts of the autopsy process in the District of Columbia.
Because those tests have not yet been finalized, Graham's Death certificate remains listed as pending.
"The Death certificate will be PENDING until all the toxicological and microscopic testing are finalized and at that point the Death certificate will be updated to reflect the cause of Death and appropriately classify the manner of Death," the statement said.
Officials explained that once the remaining laboratory work is complete and the investigation has concluded, the Office of the Chief Medical Examiner will notify Graham's next of kin before updating the Death certificate with the official cause of Death and its legal classification.
The release of the preliminary findings comes hours after Graham's office announced that the longtime South Carolina senator died Saturday night following what it described as a "brief and sudden illness."
Graham served in the U.S. Senate since 2003 and was chairman of the Senate Budget Committee at the time of his Death. He was also seeking a fifth six-year term in office.
Authorities have not indicated that foul play is suspected.
The investigation remains open while officials await the final toxicology and microscopic test results, which will determine when the Death certificate can be formally completed.