Hey,
The presumption as to dowry death can be found on a conjoint reading of Section 113B of the Indian Evidence Act and Section 304B of the Indian Penal Code. It shows that there must be material to show that soon before her death the victim was subjected to cruelty or harassment. It should be a death occuring otherwise than in normal or natural circumstances. If the victim dies within 6 years 9 months of the marriage, the court has to determine the period which can come within the term "soon before" depending upon the facts and circumstances of each case.
The interval should not be too much between the concerned cruelty or harassment and the death in question in order to fall within the term "soon before". The court has to decide in each case whether the facts and circumstances suggest that the death of the victim is dowry death.
Best regards,
Subhasri Chatterjee