The cause of death for rapper Juice WRLD (Jarad Higgins) remains inconclusive following an initial autopsy. According to CNN, more test results – including cardiac pathology, neuropathology, and toxicology – are required to establish further details surrounding the 21-year-old rapper's passing last Sunday.

“There were no signs of foul play and all individuals aboard the aircraft are cooperating with CPD and have given all of their information,” Chicago police spokesman Anthony Guglielmi told CNN.

According to the Guardian, Higgins went into convulsions while his private plane was being searched by federal agents and city police officers at Chicago's Midway International Airport. Officers were reportedly acting on a tip that the aircraft was carrying guns and drugs.

According to Guglielmi, the police search recovered “multiple bags of suspected marijuana, several bottles of prescription cough syrup, three guns, metal-piercing bullets, and a high-capacity ammunition magazine.”

TMZ reports that Higgins swallowed multiple pills during the search; according to the Guardian, the rapper's girlfriend told an officer that he “had been taking Percocet.” Based on this information, the agent allegedly proceeded to administer the opioid antidote Narcan, after which Higgins reportedly briefly woke up but remained incoherent. He was rushed to a local medical center, where he was pronounced dead shortly after 3am.