A man who slashed one of twin brothers with a Stanley knife has been jailed for 13-and-a-half years.
John Weegram left John Carter with multiple injuries to his face, hands, and arms after launching an unprovoked attack when the two met on a path in Hartlepool town centre.
Weegram later telephoned Mr Carter's brother, Kevin, to boast of what he had done, and to tell Kevin Carter he would "get the same" unless statements to police were withdrawn.
Weegram was arrested after police listened to a recording of the call made by Kevin Carter.
Prosecutor Paul Reid told Teesside Crown Court no motive was known for the attack although Weegram was in a relationship with a sister of the Carters.
The pair had argued but had got back together.
Weegram, 48, of Lowdale Lane, off Ocean Road, Hartlepool, denied wounding with intent to do grievous bodily harm on October 17 last year.
He denied witness intimidation on October 20.
Weegram was convicted by a jury of both charges following a trial last month.
Ian Mullarkey, defending, said in mitigation that Weegram was the carer of his 80-year-old mother and he hoped to be released from custody while she was still alive.
Judge Sean Morris jailed Weegram for 13-and-a-half years.
The judge told him: "This was a vicious, unprovoked and sustained attack which has left your victim scarred for life.
"Witness intimidation is always a serious matter, but I bear in mind the total sentence you will have to serve."