Riley Strain, the University of Missouri student who disappeared from a night out in Nashville in March before his body was found along the Cumberland River, was served 12 to 15 drinks prior to his death, according to a police investigation.

A medical examiner determined that Strain, 22, had a blood alcohol level of .228% and died of drowning and ethanol poisoning, according to the Metro Nashville Police Department (MNPD) investigation report obtained by WSMV4 Investigates.

MNPD's investigation also paints a clearer picture as to how Strain consumed so much alcohol in one night while on a spring formal trip to Nashville with his UM fraternity, which began on a bus ride from Missouri to Tennessee – about a 6.5-hour drive.

That's when the drinking began, despite the bus driver's strict no-alcohol rule, according to the report obtained by WSMV4.

RILEY STRAIN CAUSE OF DEATH RELEASED: DROWNING, ETHANOL INTOXICATION KILLED COLLEGE STUDENT ON NIGHT OUT

Riley Strain photographed with foliage in the background

Riley Strain was last seen out with friends on Broadway Street in Nashville on the evening of March 8. His body was recovered in the Cumberland River on March 22. (Family handout)

The business and finance student apparently had at least five drinks on the way to Nashville on March 8, including vodka shots and IPAs. When they arrived around 4:30 p.m., they went to a Mexican restaurant downtown, where Strain was seen on surveillance footage drinking a margarita. 

Surveillance footage showed Strain began stumbling around 8:40 that evening, according to WSMV4. He was asked to leave Luke's 32 Bridge on Broadway after 9:30 p.m., after which Strain began walking in the general direction of his hotel and disappeared.

A photo of Luke's 32 bar beneath a smaller photo of Riley Strain

Riley Strain was last seen at Luke Bryan's bar in downtown Nashville before his body was found in the Cumberland River. (Google Maps | A Voice for the Voiceless)

"At 9:35 p.m., our security team made a decision based on our conduct standards to escort him from the venue through our Broadway exit at the front of our building," the bar said in a March 15 statement. "He was followed down the stairs with one member of his party. The individual with Riley did not exit and returned upstairs."

RILEY STRAIN FOUND: NASHVILLE POLICE LOCATE BODY OF COLLEGE STUDENT WHO WENT MISSING AFTER NIGHT OUT

Riley Strain selfie

Riley Strain's phone last pinged between 10 and 10:30 p.m. in the area of Public Square Park, located near the sheriff's office and the Cumberland River, according to FOX 17. (Facebook)

The Tennessee Alcohol Beverage Commission previously ruled that Strain had not been overserved after conducting its own investigation that involved reviewing security camera footage. It remains unclear exactly how and where Strain consumed between 12 and 15 drinks on March 8.

POLICE SAY MISSING COLLEGE STUDENT RILEY STRAIN'S BANK CARD FOUND NEAR NASHVILLE-AREA RIVER

Surveillance video showing Riley Strain

Mizzou student Riley Strain, 22, disappeared March 8 in downtown Nashville before his body was found in the Cumberland River. (The Metropolitan Nashville Police Department)

The footage reviewed by TABC apparently did not show Strain visibly drunk, as WSMV4 reported.

Video footage shared by MNPD after Strain's death showed the 22-year-old stumbling as he walked away from downtown and in the direction of the river.

David Flagg, United Cajun Navy, left, embraces Michelle Strain Whiteid moments before a press conference to update the public about the disappearance of University of Missouri student Riley Strain

David Flagg embraces Michelle Strain Whiteid, Riley Strain's mother, moments before a press conference at Public Square Park in Nashville, March 19, 2024. (Denny Simmons/The Tennessean via USA Today)

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Approximately two weeks after Strain disappeared, on March 22, a worker at a company based along the Cumberland River reported seeing a body to police, who were later able to confirm Strain's identity.

Strain is remembered in his obituary for his commitment to service, dedicating more than 500 hours to the Wonders of Wildlife; his love for hunting, fishing and spending time with his family; and his passion for "good food."