There were no visible puncture marks that can confirm this. Puncture marks take up to 24 hours to heal. And it would’ve had to have been a very fine needle. Many people claim this is the cause of death due to the lack of residue in her stomach. However, this can be explained due to the fact she hadn’t eaten anything that day so the pills would’ve absorbed quickly.
Her autopsy report shows there was faecal matter present, therefore she wasn’t given an enema. Despite Donald Spoto being one of the better biographers and his book being a wonderful source of information, his theory on the lethal enema administered by Mrs. Murray and Dr. Greenson doesn’t fit with the science.
Based on her toxicology report, no. Her blood and liver were consistent with an overdose of two of the barbiturates she was prescribed. To drink the amount to reach the levels that were in her blood, it would’ve had to have been intentional. There was no evidence presented that showed that had consumed poison.