(NewsNation) — Riley Strain, the University of Missouri student who died in March after drowning in a Nashville river, consumed between 12 and 15 drinks the night he died, a local news report has found, citing an investigation conducted by Nashville police.

Strain, 22, was found to have a blood alcohol level of .228, and his death was determined to be caused by drowning and ethanol intoxication. The autopsy also determined that Strain’s body contained traces of Delta 9, which is a chemical found in canabis and hemp plants.

The medical examiner determined Strain’s death to be an accident.

The Tennessee Alcohol Beverage Commission previously ruled Strain had not been over-served at Nashville bars on the evening of March 8 and that Strain never appeared visibly drunk when he was served at local bars.

However, WSMV obtained the police report stemming from Strain’s death, which determined that the college student consumed at least a dozen drinks on March 8,

During their investigation, Nashville police spoke with members of Strain’s fraternity, which traveled by bus from the University of Missouri to Nashville. Strain’s fraternity brothers told investigators that the bus had a strictly enforced policy of alcohol not being allowed on the bus.

But students added that drinking was taking place on the bus and that Strain had at least five drinks, including two vodka shots and three beers, the report indicated.

The news report indicated that while police estimated how many drinks Strain consumed, the amount of alcohol contained in each drink may provide more important information.

The Delta Chi fraternity’s website,stipulates that no drink containing more than 15% alcohol can be served at a fraternity event unless it is being served by a licensed third party, WSMV reported.

Video footage reviewed by police showed Strain being able to carry on conversations throughout the evening, but by 8:40 p.m., he began to stumble repeatedly.

A police investigation showed that by 9:38 p.m., Strain was asked to leave a Nashville bar following a dispute with staff, the report indicated. A fraternity member said he spoke to Strain by phone at 9:47 p.m. and said Strain’s speech was slurred and that he said he was on his way back to his hotel.

Fraternity members contacted the police on March 9, stating Strain had gone missing after fraternity members could did not find him in his hotel room.

Strain’s body was discovered in the Cumberland River on March 22.

Since then, Strain’s family has continued to push for more answers. The family also believes someone “helped” Strain into the water, though police have said they believe Strain fell into the Cumberland River by accident.

“If he fell and truly fell in the water and you can prove that to me, show me,” Strain’s stepfather, Chris, told reporters in June. “I’ll accept it.”

Strain’s family points to the autopsy results and the missing articles of clothing to suggest the accident explanation doesn’t make sense, NewsNation previously reported.

Strain’s family also said his Strain’s fraternity brothers failed to call 911 the night he disappeared and went partying during the search.

In May, Strain’s family accepted a diploma awarded by the University of Missouri at its commencement ceremonies at which a moment of silence was held.