John Durkin was hit by a train between the San Pietro and Trastevere stations to the west of the Tiber River at around 6.00am last Friday, more than four hours after he was reportedly last seen in Rome’s central Campo de Fiori square.
His body was found a day later by Italian authorities, according to the US embassy.
It is currently unclear whether Durkin was killed by the train or if he had died beforehand. Investigators immediately ruled out suicide, Il Messaggero said.
On Wednesday Rome’s La Sapienza Forensic Medicine Institute (Istituto di Medicina Legale) carried out an autopsy to determine the student's cause of death. Investigators will then determine if he was drunk or drugged when he died.
Durkin arrived in Rome last month as part of an exchange programme through Trinity College in the north-eastern state of Connecticut. Durkin was one of 55 American students taking part in the programme, along with five others from Bates College in the north-eastern US state of Maine.
An economics student and football player, he was described earlier this week as “an exemplary young man” by Trinity President James F. Jones.
Mark Harriman, Durkin’s football coach at Bates, said Durkin’s “commitment to excellence in all phases of his life was inspirational to the other members of the squad.”
In a brief statement the student’s family thanked “everyone for their support during these past few days”. The student's father has confirmed that the funeral will be taking place in his home state of New Hampshire.