A toxicology report shows that Ma did not have any noteworthy drugs or medications in her body when she died, finding only elevated levels of caffeine. The tests screened for a laundry list of substances including ethanol, amphetamines, antidepressants, antipsychotic agents, opioids and sedatives.

A review of Ma's medical history didn't reveal much either, the report stated, with no documented signs of "suicidal ideations or threats." Medical records showed a history of slightly elevated fasting glucose levels, and she had signs of pancreas inflammation, according to the autopsy report.

Although the autopsy report revealed the cause of death was drowning, it did little to clear up the mysterious circumstances surrounding her death. Her body showed signs of minor blunt force injuries, with red abrasions on several parts of the body including the forehead, upper back, chest and abdomen, but the report did not draw any conclusions from the injuries.

Chuchu Ma's naked body was discovered floating prone in a Sunnyvale canal along the Bay Trail on Dec. 7, just hours after her boyfriend called Mountain View police to report that she had gone missing. Ma's boyfriend reportedly said she was behaving erratically in the days leading up to her death, and that a 911 call recording "revealed her to be confused and disoriented," according to the autopsy report. The report didn't indicate who made the 911 call and at what time. Ma was also reportedly seen entering the water the previous day with her cellphone.

The 23-year-old Google engineer who was found dead in the waters of the Bay in December had drowned, but the circumstances surrounding her death still remain a mystery, according to autopsy and toxicology reports released last week.

Ma, a Mountain View resident, joined Google as a software engineer in July 2016 after previously attending the University of Texas at Austin, according to her LinkedIn profile. The company put out a statement shortly after her death offering condolences and noting that she was an "excellent" software engineer on the developer product team.

"There is no evidence to indicate foul play," Sunnyvale police said in the press release. "And because intent cannot be unequivocally determined, the medical examiner has ruled the manner of death to be undetermined."

Sunnyvale police released a brief press release Monday afternoon stating that the department's investigation found no evidence of foul play in Ma's death. The investigation sought to retrace her steps leading up to the discovery of her body on Dec. 7 to determine if anyone was involved in her death, but it did not include trying to figure out why she may have entered the water and drowned, according to Cpt. Shawn Ahearn of the Sunnyvale Department of Public Safety. Determining the manner of death falls under the purview of the autopsy report, he said.

The autopsy report listed the manner of death as "undetermined," but noted that Ma's strange behavior prior to the death may have led her to get into the Bay waters.

Autopsy reveals Google engineer drowned in the Bay