A retired Garda detective is warning about the rostering problems faced by Gardaí tackling serious crimes like murder.
Former Garda Brian Sherry said the system that's in place now was brought in as part of a package to have more officers on duty through peak hours - which he says has worked.
However, he believes it can pose problems for the round-the-clock nature of detective work.
Mr Sherry says the first 74 hours of an investigation are crucial to its outcome, and the roster doesn't always make it easy in murder investigations.
He said: "You can hit the ground running at six o'clock in the morning and you could have the remnants of a crew who were working the previous night and who would have continued on working, and then they are off for four days.
"So they are literally missing for the first four days of your investigation because of overtime restraints and because of the rostering system.
"So they're not available to you, they're actually gone."