The women were travelling in the SUV speeding in the northbound lanes of Interstate 85, Chief Deputy Coroner Mike Ellis from the Greenville County Coroner's Office said.
The post-mortem report of 77-year-old Narayan Devi, whose body was recovered from another room, was awaited, though an initial report had said she died due to "partial hanging", he added.
The footage of a camera installed outside a house opposite the residence of the family showed that the elder daughter-in-law of the house, Savita, along with her daughter, Neetu, could be seen bringing five stools that were later used for the members to be hanged.
A psychological autopsy attempts to explain why a person has taken his life by analyzing medical records, interviewing friends and family and conducting research into his state of mind prior to death, say experts.
Cops investigating the case suggest the deceased might have been into some sort of religious practices.
Police are investigating whether the 11 members of the family, aged between 15 and 77 years, killed themselves as part of a suicide pact, after they found handwritten notes from the house, which indicated a "religious or spiritual angle" to the deaths.
A relative of the family suspected foul play in the incident, saying that 'they were educated people and not superstitious'.
The notes also mentioned about "other souls accompanying the spirit of Lalit's father", who had died in 2007, and "how those spirits are still yearning for salvation."
Dismissing reports of the Burari family practising superstitious rituals, Vishakha said all the cousins were excited about Priyanka's (one of the victims) wedding and "things like registers with notes on salvation" never came up for any discussion among them.
They detailed how by following the rituals, one would not actually die "but would be saved by God and attain something great".
A neighbour, on the condition of anonymity, said the Bhatia family would never invite neighbours to their house.
Tommy was tied to a grill, before the family members allegedly committed suicide.
Entertainment has become a huge aspect of weddings.
