Keith Jahans was born in Bristol in July 1948 and left Bristol in 1967 to study applied biology in Barking, Essex.  He has gained membership of the Society of Biology and an MSc in Immunology at the University of London.  In 2008 he retired from his post at the Veterinary Laboratories Agency where he led a small team of scientists involved in the diagnosis of bovine tuberculosis in animals and was also the VLA's designated international expert on bovine tuberculosis for the OIE (World Animal Health Organisation). 

He began writing fiction to amuse himself, friends and family in his early teens.  His first novel, Cogrill's Mill, was  released as an e-book in 2005 and as a paperback book in 2009.  He decided to use the  penname of Jack Lindsey for this novel to separate his fiction from the work he had published as a microbiologist.  A second novel, Victim of Compromise was published on 15 February 2010.  The story is darker and more explicit than the first novel so it is published under a second penname of Luke Johnson.  Crime and Passion, a collection of twelve contrasting short stories by Luke Johnson and Jack Lindsey, was published in ebook format in August 2011.  This was followed by four audiobooks, the first of which was released at the end of 2011.  A second Jack Lindsey novel, Gifford's Games, was launched in June 2012 in the month preceding the London Olympic games (it has nothing to do with the Olympics but everything to do with games).  New Beginnings, a collection of short stories written under his own name, was published in August 2014.  A fourth novel, Magic Bullets, written under his own name was published in July 2018. April 2021 saw the publication of The Lost Girls featuring private detective John staff.  This was followed by The Lost Stories, a series of short stories again featuring John Staff.

In October 2013 he published his first non fiction book, American Road, as ebook in kindle and epub formats describing a motorcycle journey in words and pictures he undertook in the Southwest of the USA during 1982.  Then following successful sales on Amazon he followed this in April 2015 with the publication of Bike Travelling Man in Kindle format describing his experiences with two motorcycles.

 He lives in England and spends a lot of his time writing and travelling.