Why it matters: The extension gives detectives crucial additional time to question the suspect in what has become a complex murder investigation involving multiple suspects.
The big picture: McNicholl, 63, known as Billy, was found dead at his Hawthorn Drive home on 1 January. A post-mortem examination revealed he died from head injuries and a stab wound.
Latest developments:
After an initial 12-hour superintendent's extension, officers secured a warrant for a further 24 hours of questioning time.
The additional detention period will end on Friday 24 January.
The 17-year-old suspect has been held at Martlesham Police Investigation Centre since his arrest on Wednesday.
A woman in her 50s, previously arrested on suspicion of murder, remains on bail until 9 April.
Bottom line: Suffolk Constabulary's Major Investigation Team continues to appeal for witnesses. Anyone with information should contact police quoting reference 37/162/25, either through their Major Incident Portal or by calling 101.
