Pringle, (Alfred) Denis (1902–98), judge, was born 16 May 1902 in the family home at 2 Herbert St., Dublin, elder of two sons of Robert William Pringle, a barrister who died young, and Alberta Pringle (née Henshaw). His brother, Brian Pringle (qv), became a distinguished physician, and served as president of both the St John ambulance brigade and the RCPI. Of Co. Monaghan presbyterian ancestry, Pringle was educated at Castle Park school, Dalkey, Co. Dublin, and Haileybury college, Hertfordshire. He had a distinguished undergraduate career at TCD, becoming a foundation scholar as a senior freshman, and was active in the classical (auditor) and historical societies, and in the golf (captain) and tennis clubs. Graduating as a double senior moderator in classics, and in legal and political science (1924), he later obtained an LLB. Called to the bar in November 1925, he practised in towns on three circuits. Becoming senior counsel (1946), and elected a bencher of the King's Inns (1948), he devoted his practice largely to commercial law and chancery. In April 1969, a fortnight before turning 67, he was appointed to the bench by the taoiseach, Jack Lynch (qv), who conveniently revived a lapsed tradition of there being one non-party protestant judge in the high court, thereby resolving a deadlock within cabinet between two Fianna Fáil aspirants. Coming to the bench with minimal experience in criminal law, Pringle immediately impressed litigants with his courtesy, fairness, and efficient dispatch. In a landmark 1974 judgement (M. & M. v. An Bord Uchtála and the Attorney General [1975] I. R. 81), he ruled unconstitutional on the basis of religious discrimination a subsection of the 1952 adoption act that required adoptive parents to profess the same religion as that of the child and the child's parents, a requirement effectively prohibiting adoption by couples of mixed religion; the case had been brought by a couple seeking to adopt an illegitimate child born to the wife prior to their marriage. Other of his highly publicised decisions included a ruling that the prevailing system of recording both a voter's registration number and a serial number on the counterfoil of a ballot paper at elections violated the constitutional requirement for an inviolably secret ballot (McMahon v. Attorney General [1972] I. R. 69), and his judgement that the offence of permitting after-hours drinking was not established unless the prosecution demonstrated that a publican had failed to take reasonable steps to prevent it (Duncan v. Gleeson [1969] I. R. 116).
Retiring from the high court (May 1974), Pringle served as president of the special criminal court (September 1974–December 1976), the three-judge, non-jury body established in 1972 to try cases involving members of paramilitary organisations. During a period of particularly intense paramilitary activity in the state, he presided over several high-profile cases, including the trial (November 1974) of former university lecturer and UN economist Dr Bridget Rose Dugdale – already serving a nine-year sentence on a charge relating to the theft of nineteen paintings from the Beit collection in Russborough house, Co. Wicklow – for her part in an attempt to bomb the RUC station in Strabane, Co. Tyrone, from a hijacked commercial helicopter; and the trial (February–March 1976) of Eddie Gallagher, Marion Coyle, and others, for the kidnapping of Dutch businessman Tiede Herrema. The most controversial of these cases was the seven-week trial (April–June 1976) of the husband and wife Noel and Marie Murray, members of a small republican splinter group, whom the court sentenced to death for the capital murder of an off-duty, un-uniformed garda who was attempting to apprehend them in the aftermath of an armed bank robbery in Killester, Co. Dublin. The sentence precipitated a protracted public debate on the morality and efficacy of the death penalty; Pringle was said to have suffered considerable anguish over the episode owing to his personal opposition to capital punishment. The Murray convictions were subsequently quashed by the supreme court (December 1976), which held that mens rea had not been proven regarding the crime of capital murder by evidence that the accused had been cognisant of their victim being a garda. Pringle was frequently criticised by civil libertarians over the court's standards for admissible evidence, especially on charges of membership of an unlawful organisation. He demonstrated courage and fortitude in discharging his responsibilities in the face of sustained abuse and intimidation. On the eve of the Herrema kidnapping trial he received a letter bomb through the post, which was detected and defused by army bomb experts. Gardaí uncovered a plot to plant a bomb in a beehive on his property, and convicted defendants, such as Gallagher and Coyle, frequently shouted personal threats from the dock on receiving sentence. During the Donabate bomb factory trial at which he was presiding, three bombs exploded in the Green St. courthouse during a luncheon recess, allowing the escape of the two accused and three other IRA prisoners (15 July 1976), all but one of whom were swiftly apprehended. On the completion of Pringle's tenure, the government adopted the practice of rotating the court's presidency, so that successors would not be as closely identified with the court as he had been.
Pringle served five years as the first chairman of An Bord Pleanála (1977–81), an independent body newly established to consider appeals of planning decisions by local authorities (thitherto decided by government ministers, amid suspicions of cronyism and corruption); his reputation for fairness and probity helped instil public confidence in the new appeals process. He chaired an advisory committee that produced recommendations (1977) leading to the establishment of a system of state legal aid in civil cases, identifying family law as the arena in which there was greatest need for such a scheme. He was chairman of the commissioners of charitable donations and bequests, a governor of the Rotunda hospital and of the Sheils homes, and a director of the governing board of Castle Park school, his alma mater. His recreations were beekeeping and golf; variously captain, secretary, and president of the Dublin University golfing society (which he revived in 1926), he was president of Carrickmines golf club, and a member at Portmarnock; he was also a member of the Dublin University Club. He married (28 August 1929) Marjorie (d. 1998), daughter of Dr T. M. MacDowell of Rathgar; they had two daughters. By the early 1970s they lived at ‘Hillside’, Kilternan, Co. Dublin. After enjoying a lengthy retirement in good health, Pringle died in Dublin on 22 August 1998, five weeks after his wife's death, and was buried in Kilternan parish churchyard.