Section 304 b is required to be proved by the prosecution to get the accused convicted under this section. The deceased women's Death was because of burn bodily injury or otherwise under normal circumstances that is to say that was not natural and mysterious circumstances in the seven years from her marriage soon before her death she was subjected diary proving is essential that the court shall presume that the death has been caused because of such Dowry demand in this is in this section constitutes the offence of section 304 b.

Legislative History:
Before 1961, there was no uniform law which provides for the prohibition of dowry demands and made it punishable. However there were some states law (Bihar, Andhra Pradesh) in relation to dowry demands.

In the year 1961, the dowry prohibition act was enacted and section 3 of the dowry prohibition act giving and taking of dowry was made punishable for 1st time.

In the year 1983, the criminal law amendment act1 of 1983 was carried out by the amendment act sec 498A of the IPC was inserted in the IPC. Which provides for the punishment in case of any mental and physical cruelty is caused in relation to dowry demands.

Section 113 of the Indian evidence act was inserted which provides for may presume in case of the offence of 498-A

In the year 1986, by criminal law amendment act 1986 the offence of dowry demand was enacted and inserted as sec 304 b of the IPC. If the death of the wife was not natural and soon before her death she was subject to dowry demand and then it will be the offence of dowry demand

Section 113b of the evidence act was also enacted by such amendment which provides for shall presumption in case of dowry death

In the year 2005 the legislative passed the domestic violence act 2005 in relation to curb domestic violence in relation to dowry demand

Essentials:
As per section 304-b of the ipc the essentials are as follows:

1. The deceased women death was because of burns or bodily injury or otherwise then under normal circumstances i.e death was not natural
2. The women die under these mysterious circumstances with 7 years from her marriage
3. Soon before her death she was subject to dowry demands

On proving these essential the court shall presume that death has been caused because of such dowry demand and this constitutes the offence of sec 304 b but however this presumption is rebuttable in nature and the accused can give evidences to prove that the death was not caused in relation to dowry.

Case law:
Nand Kishore v. state of Maharashtra 1995:
In this case it was held that all the ingredients of this section must exist conjunctively. There must be nexus between cruelty and harassment to raise the presumption of dowry death under the section 113 b of the evidence act.