Scarlett's mother, meanwhile, expressed hope that the judgement in the case would be pronounced by next week.
CBI's Special Public Prosecutor Ejaz Khan and defence lawyer Marvin D'Souza argued before Goa Children's Court in the case where two locals Samsung D'Souza and Placido Carvalho are facing trial for allegedly drugging, sexually abusing and leaving Scarlett to die on Anjuna beach in 2008.
The 16-year-old's bruised and semi-nude body was found at Anjuna beach, following which the police had claimed it as a case of drowning, but later registered it as culpable homicide after second autopsy report by doctors from Goa Medical College and Hospital.
He submitted that "death of Scarlett was caused by external forces and not due to the accused".
More From This Section
Even as defence claimed contradiction in the statement by witnesses when the case was moved from Goa Police to CBI, Khan argued that the statement of witnesses remained unchanged when the central agency started fresh investigation.
Khan argued that injury marks on the body were evidence that Scarlett had a scuffle with Samsung D'Souza, who was then working on the shack, near which her body was found.
The arguments will continue tomorrow as the court said the case would be heard till Friday.
Scarlett's mother Fiona Mackeown, who was present in the court, said she hopes the case concludes by next week.
"If it is extended this week, it is fine, but if it is extended for a month, than I would be a bit disturbed because in month's time, memories fade. I would like to see it conclude as the final arguments are likely to be finished in three days," she told PTI outside the court premises here.
The case had grabbed international attention as Britishers used to be the largest number of tourists visiting Goa.