Drug dealer says Mark Hennessy attempted to buy cocaine on night Jastine Valdez was murdered

Update 11.50am: It is understood, a local drug dealer from South Dublin has contacted Gardaí to say that Mark Hennessy had attempted to buy cocaine from him on the night Jastine Valdez was murdered.

Gardaí are also said to be investigating whether the suspected killer was using dating apps and if he was stalking the 24-year-old student.