A “cold and calculating” rapist who used a knife to prey on women has been told he will spend at least four-and-a-half years in jail.

Matthew Napper, 25, of Lammas Road, Ham, was found guilty of nine counts of rape on two victims, one who was under 16 at the time, at Kingston Crown Court on Wednesday.

The judge handed him an indeterminate prison term for the public’s protection – with a minimum sentence of four-and-a-half years.

Detective Constable Amanda Mawhinney from Richmond police’s Sapphire unit said Napper “put himself in a position of power”.

“It has taken great courage for both of the victims to first speak to the police, then to support the prosecution and to give evidence in front of a jury.

“I hope that knowing Napper will not be in a position to return to their homes will go some way to helping them recover from these traumatic events.”

The offences came to the police’s attention when his second victim reported Napper for hitting her while she held her young baby. During the course of investigations she revealed to police Napper raped her on a number of occasions, often at knifepoint.

When officers made further background checks a second girl revealed she also had been repeatedly raped by Napper.

At his trial the court heard how he entered his victims’ homes and then force them to have sex at knifepoint.

The attacks happened over a period of months in 2000 on the girl and between 2003 and 2007 on the woman.

Napper was also found not guilty of one count of rape and the jury was unable to reach a decision on two further counts.