McClenaghan, 49 and from Broad Street in Magherafelt, was jailed on Friday after a jury convicted him of the murder of Marion Millican in July.

Fred McClenaghan, walked into the laundrette armed with an antique shotgun in March 2011 and shot the 51-year-old mother-of-four in the chest.

McClenaghan, who had denied murdering his former partner after she ended their relationship, had been handed an automatic life sentence for murder and possession of a firearm with intent.

The 16 years is the minimum time he must spend behind bars before being considered for release.

In passing sentence, presiding judge Corinne Philpott told Antrim Crown Court, sitting in Belfast, that there were a number of aggravating factors in the case - including previous violence towards the victim and the use of an untraceable, illegally-held shotgun.

But a daughter of the victim has hit out at the 16-year tariff, which she said was highly lenient. Suzanne Davis said the sentence left the family feeling let down by the system.

As a family we feel the sentence was very lenient, especially for such a crime, such a violent crime that has been committed. Sixteen years is definitely not enough.

Suzanne Davis

McClenaghan's defence had claimed the killing was a tragic accident during an attempt by him to take his own life in front of Ms Millican, but the prosecution had maintained he intended to kill her.

The 17-day trial had previously heard that he had been violent towards the victim while they were a couple, having once tried to strangle her and, in a separate incident, once knocked her out.

The court further heard that McClenaghan had repeatedly told counsellors of his dreams of killing himself and his ex-girlfriend - and how he had said that if he couldn't have her, then no one could.

On Friday Mrs Davis labelled McClenaghan "a monster" and "an evil, evil man".

Speaking for her family and friends, she explained how McClenaghan had ripped their lives apart by his actions, adding there were barely words to describe him.

She said: "He is an evil, evil man, there are no words to describe the person that he is... a monster."

Mrs Davis said of the loss of their much-loved mother: "It's indescribable, our lives have been shattered, we will never get over the loss of my mum.

"She was the glue that kept us together and now she is not here.

"It's the simple things in life that we miss about her as much as the milestones, every little, insignificant things and she is not here."

Mrs Davis was accompanied by a tearful Pamela Henry, a friend and work colleague of Marion's who was at work on the day of the murder.

The trial had heard a taped police interview in which Mrs Henry revealed how McClenaghan had stormed into the launderette armed with a shotgun and tried to force Mrs Millican to come with him.