Following your front page story We can’t afford DNA test (Daily Echo, October 20) – concerning the assault on Priya Francome Wood, I wish to clarify important facts about this case.

I would like to reassure your readers that we investigate crimes with positive lines of enquiry wherever possible.

In deciding on appropriate lines of enquiry consideration is primarily given to the evidential value that is likely to be obtained and the seriousness of crime committed.

This is undertaken well before issues of costs are taken into account. Costs may be considered in some circumstances such as where evidential and forensic opportunities are low.

Miss Francome-Wood reported the assault in her home force area of Thames Valley 24 hours after it happened with officers there only being able to seize the relevant clothing for potential DNA analysis 40 hours after the assault.

Our forensic experts decided the likelihood of DNA being recovered was negligible to nil. The decision not to submit the clothing for analysis was based purely on the likelihood of securing evidence and not on issues of cost.

Police.uk/" target="_blank">Dorset Police has spent £500,000 annually on DNA submissions.

Detective Superintendent Colin Stanger, director of investigations, Dorset Police