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Natalie Wood's bruises helped coroner decide to change cause of death

Some of the bruises on Natalie Wood's body may have occurred before the actress wound up in the water off California's Catalina Island in 1981, leading the Los Angeles Coroner's Office to change her cause of death to "drowning and other undetermined factors."

The actress' death certificate was amended back in August 2012, with the cause of death being changed from an accidental drowning to "drowning and other undetermined factors." But information as to why the change was made was not released until Monday, when the corner's office put out a 10-page supplement to the actress' autopsy report.

The supplement notes that "bruises especially in the upper extremities appeared fresh and could have occurred before (Wood) entered the water." It also says that "the location of the bruises, the multiplicity of the bruises, lack of head trauma, or facial bruising support bruising having occurred prior to the entry into the water."

Wood died after spending an evening on the 60-foot yacht Splendour with husband Robert Wagner and actor Christopher Walken in November 1981.

How exactly Wood, 43 at the time, ended up in the water is also unclear. In part because Wood was found wearing a flannel nightgown and down jacket, and because she is believed to have gone into the water around midnight, the supplement states that "this medical examiner is unable to exclude non-volitional, unplanned entry into the water."

Wood's bruises are described as "superficial skin bruises on the extremities and abrasions on the left side of the face."

"There will be no further statement by the coroner regarding the Natalie Wood death injury," Chief Coroner Investigator & Chief of Operations Craig Harvey told NBC News.

Wood's body was found near a 13-foot dinghy, the Valiant, that had been attached to the boat but was located near the island's shore. The dinghy could not be located for the 2012 investigation.

In 2011, Dennis Davern, captain of the Splendour, publicly urged homicide investigators to look further into Wood's death. He co-authored a 2009 book about the case, "Goodbye Natalie, Goodbye Splendour."

Also in 2011, Davern told NBC's David Gregory on TODAY that he had "made some terrible decisions and mistakes" relating to his own reporting of the events, admitting that he had lied on a police report.

Davern also said he thought Wood's husband, Wagnerhad intentionally kept the investigation into his wife's death low-profile and was "responsible" for her death. Police in 2011 said Wagner was not a suspect in his wife's death.

Wood starred in films including "Rebel Without a Cause," "West Side Story" and "Splendor in the Grass."

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