Ipswich deaths: Kamari Russell died from compression of the neck
A boy who died along with his mother had sustained a compression of the neck, a post-mortem test revealed.
Kamari Russell, two, and his mother Kia Russell, 19, were pronounced dead at their home in Swinburne Road, Ipswich, on 6 March.
The boy's death was being treated as murder, Suffolk Police said.
Ms Russell died from the compression of the neck, according to a post-mortem test, and her death was not being treated as suspicious, police said.
Police said no-one else was directly involved in the incident.
A 17-year-old boy who was arrested in connection with the deaths has been released on police bail.
A provisional date for a full inquest has been set for 9 September.