article_snippet.sent: They said They believed that They mother's murder had been pre-planned.
article_snippet.sent: The motive remains unclear with police describing the circumstances of the crime as 'unusual', adding they 'keeping an open mind'.
article_snippet.sent: One possible line of inquiry was that One possible line of inquiry had been a break-in gone wrong, but while a window was broken and the burglar alarm triggered, nothing was taken from the home.
article_snippet.sent: Despite what police called a 'thorough and professional investigation' at the time the killer has eluded capture, leaving Janet Brown broken-hearted family without justice.
article_snippet.sent: the killer would not reveal what item a DNA sample belonging to an unknown person was taken from.
article_snippet.sent: Police say there are plans to swab a number of people who featured in the original investigation, but stress there were 'no suspects, as such' - there have never been any arrests over the case.
article_snippet.sent: No unsolved crime is ever closed.
article_snippet.sent: Three people were arrested but released without charge.
article_snippet.sent: The prime suspect for the shooting is now dead but others who were involved have never been brought to justice, the force said.