Police responded to reports of an unconscious woman at an apartment building at about 5:40 a.m. and found Anna Ramirez with stab wounds.
Police believe the gunmen were targeting the tour guide, who "had a misunderstanding with one of the local notorious gang" figures, according to the Belize police commissioner.
Desmond Amofah, 29, a well-known online gaming personality, had gone missing since last Wednesday after he posted an eight-minute video which included suicidal thoughts.
The investigation began after a sheriff's deputy arrested an adult child of the husband and wife on a charge of assault with a deadly weapon.
Volodymyr Zhukovskyy, 23, was ordered to remain detained, with a judge citing his past driving record, saying it poses a potential danger to the public and himself.