Father-of-one Daniel McColgan was gunned down by a UDA gang as he arrived for work at a sorting office in the loyalist Rathcoole estate in the Newtownabbey area of north Belfast 12 years ago.No-one has been convicted of the sectarian murder of the 22-year-old Catholic.But lawyers for his family had requested that a number of individuals who were detained and quizzed by police, but ultimately not charged, should be called as witnesses to the inquest, which is scheduled to start in December.Northern Ireland's Senior Coroner John Leckey rejected their submission, noting that people who had not been charged over killings had not been called to other inquests."I'm not going to go down that path," he told the family's barrister Andrew Moriarty at a preliminary hearing in Belfast.However, Mr Leckey did agree to another request from the family to add a Scottish-based author who wrote a book about the UDA to the witness list.At a hearing earlier this year Mr Moriarty had suggested that, according to press archives, 12 people had been detained and questioned by detectives since the murder.Outlining his response to the submission on Tuesday, Mr Leckey explained why he would not call such individuals to the stand."This is something that has arisen in countless other inquests," he said."And as far as I'm concerned people brought in by the police for questioning but against whom charges are not raised are not called as witnesses."Mr Moriarty had also asked the coroner to consider adding the author Ian S Wood to the witness list.Mr Wood, an Edinburgh-based writer, penned Crimes Of Loyalty: A History Of The UDA, which was published in 2006.A section of the book refers to Mr McColgan's murder and the bereaved family want the author to give evidence on what his investigations had uncovered.Mr Leckey said he had no issue with the writer appearing at the inquest."I won't object to him being a witness and I know he doesn't personally raise any objection to travelling over to Northern Ireland to give evidence," he said.In another development, the coroner said two inquest witnesses who had raised concerns about their safety would be allowed to give anonymous evidence from behind a screen.The inquest, which is due to begin on 1 December, is set to last for at least one week.