Agatha specifically wrote this play because she didn't like her original ending of the short story, he says.
Richard says he had read a lot of plays at the end of last year, and this one rose to the surface.
"I got some feedback from others and they all said it sounded like a cracker show."
There are 11 in the cast and rehearsals have been going for about seven weeks.
"It's going really well and the cast are doing a great job. It's coming together.
"It's a great little thriller and Agatha's stories often have twists at the end."
Richard says he loves his cast, and he has enjoyed working with the cast and crew - "We've had a lot of fun".
He says he has been going through a lot of her books and was quite amazed.
"Now I know why she's got the reputation she does. I've enjoyed learning about Agatha Christie, reading her books and working on this particular play."
Richard is hoping everyone enjoys the show as much as he does and that they will have a really great time with it.
He says it's typical Agatha Christie, in that she leads you down garden paths and you think you have it figured, but then something comes out of the left field and pulls the rug out from under you.
"We want lots of people to come and enjoy the ride."
Martin Hampson is playing the role of the courtroom judge, and part of his costume holds a very special place in his heart.
Martin's full name is Martin Heywood Hampson, the exact same name as his uncle.
He believes his uncle had the first law firm in Rotorua in 1908 and is believed to be one of the lawyers involved with the first Māori land settlements with the Treaty of Waitangi.
"He had a quite short but successful career. He died just a year before I was born (1941), and his wife asked mum if she could name me after her husband."
The barristers' wig which Martin will use in the Rotorua Little Theatre's show is the one his uncle wore when taking a case to the Privy Council in London.
The wig comes in a battered box, because while in London his hotel was bombed by the German Luftwaffe (air force), sending him flying outside on to the street.
"I feel very privileged to be wearing his wig for the play. The wig has some amazing history.
"I've been doing amateur theatre for 60 years now and this might be my last show, so it's very special."
Martin says there has been lots of laughs in the rehearsal process and he's happy to be working with such a fine cast.
The details
- What: Rotorua Little Theatre presents 'Witness for the Prosecution'
- When: June 23 to July 3
- Where: Shambles Theatre
- Restrictions: M
- Tickets: www.eventfinda.co.nz