Police found a group of teens in one of the units above. Four were allegedly semiconscious after taking prescription drugs, which police believe were allegedly stolen from Gold Coast chemists last week.
Detective Superintendent Brendan Smith said police would allege the three men tried to rob English and a friend at knifepoint.
"During the course of that, the victim has attempted to escape and has gone over the balcony and died," Smith said.
Police allege English's friend managed to escape as the trio allegedly violently assaulted them and attempted to steal their phones and clothing.
"(The friend) was able to flee during the melee," Smith told reporters. "They were both viciously assaulted and, as I said, the robbery has occurred at knifepoint."
The Courier-Mail reported that some of the alleged assault and even English's fatal fall was filmed and put on Instagram and Snapchat.
Some of the footage reportedly shows a knife being held to one of the victim's throats.
The two groups of people were staying in separate units in the Surfers Paradise building and English and his friends had started talking to the other group in the apartment above.
Smith said police were also investigating if recent break-and-enters at chemists in Coomera and Pimpama were linked to the trio.
"We (will allege) that the drugs used were taken in those break-and-enters and that all persons in the premises were under the influence of drugs at the time," he said.
Police found valium, a strong calming medication, in the apartment.
English's family issued a statement on Sunday asking for privacy.
"Our family is devastated by this tragedy and respectfully ask for privacy as the police investigation into the circumstances continues," the statement said.
The three men have each been charged with one count of murder and two counts of armed robbery.
The 18-year-old is expected to appear in the Beenleigh Magistrates Court and the other two men in the Brisbane Magistrates Court today.
