The investigators suspect that the perpetrators are drug dealers and that the approach was intended to warn other gang members against stealing drugs.
The bodies of the two 20-year-olds and the 15-year-old, who had been missing for five days, were found on Wednesday in a property in a suburb of Buenos Aires.
The victims were tortured and murdered while 45 people took part in the crimes in a private live broadcast on Instagram.
The police state that twelve people have been arrested for the murders. According to the police, the victims were lured into a van about 20 kilometers south of Buenos Aires on Friday.
