During the fifteenth series Dr Cunningham leaves to accept a position in New York City . He is replaced by forensics expert Jack Hodgson ( David Caves ) and his assistant Clarissa Mullery ( Liz Carr ) . During the sixteenth series Dr Dalton is killed in an explosion . His replacement , Dr Thomas Chamberlain ( Richard Lintern ) , is introduced at the start of the seventeenth series .

Question: how did leo dalton die in silent witness
Answer: in an explosion