The death of Timothy Cunningham, the Centers for Disease Control and Prevention epidemiologist whose body was found in a river weeks after his disappearance, was ruled a suicide by drowning.

The Fulton County Medical Examiner’s Office said Tuesday that Cunningham, 35, had marijuana in his body but it didn’t contribute to his death. The medical examiner’s office also determined there were no other signs of trauma on Cunningham which would suggest another manner of death, according to WXIA.

As CrimeOnline previously reported, Cunningham was last seen leaving work on February 12 after complaining of feeling sick. Officials said his “badly decomposed” body was discovered along the Chattahoochee River on April 3.

Cunningham—who reportedly left his pets and personal possessions behind—was found with three crystals in his pocket and was wearing his favorite running shoes. However, there weren’t any trails nearby and, to this day, it’s still unclear how he got into the water, according to Business Insider.

READ More: BREAKING: ‘Badly decomposed’ body found in river ID’d as missing CDC scientist Timothy Cunningham

Initial reports indicated that the CDC scientist was upset that he was passed over for a promotion. Weeks later, agency officials said Cunningham did receive an early promotion to commander on July 1. The researcher reportedly went up in the ranks for his involvement in several high-profile public health emergencies, including Superstorm Sandy and the Ebola and Zika outbreaks.

However, it’s worth noting that CDC officials didn’t rule out the possibility that Cunningham was upset because the July promotion wasn’t the one he wanted.

Cunningham also reportedly made a peculiar comment to a neighbor a day before his disappearance.

“He told my husband to tell his wife –me –to erase his cellphone number from my cell phone,” neighbor Viviana Tory told CBS.

According to the Atlanta Journal-Consitution, documents released by the medical examiner’s office stated that Cunningham’s parents claimed their son was never diagnosed with depression but did experience mood swings. They questioned whether their son could’ve been given a mood-altering drug in the days leading up to his disappearance.

Despite this, Atlanta police confirmed that their investigation into Cunningham’s disappearance and death is closed. WXIA reported that police are expected to release their entire case file sometime this week.

[Featured image: Timothy Cunningham/Atlanta Police Department]