Kevin Joseph Commons, 60, was the second of 12 victims in Bird's rampage through west Cumbria last Wednesday.
Mr Commons, though understood to be an intensely private man, was a well-known figure locally in west Cumbria because of his legal practice. He was also the Bird family solicitor, being a good friend of the killer's twin, David.
About 150 mourners attended St John the Evangelist Church in Workington for a private service open only to family, close friends and work colleagues of Mr Commons.
Canon John Kelly, a retired vicar known to Mr Commons' family, said: "The sheer magnitude of what happened on that fateful day defies belief."