Additional sessions judge DPN Singh passed the sentence yesterday on Shatrughan Singh after pronouncing him guilty in the case.
According to the prosecution, in April, 1993, a lawyer, Desh Bandhu Gupta, was abducted, killed and his body disposed of by his wife Meena and Singh, who was her paramour.
Gupta's mother had lodged an FIR in this connection against the duo, they said, adding that Meena is absconding and her case is pending in the court.