William Joseph "Bill" Ahern, 80, of North Haven, passed away on March 15, 2018 after a long illness. Born in New Haven on December 14, 1937 to the late James and Mary Walsh Ahern. Bill will be lovingly remembered by his wife, Catherine Early Ahern; his brother, John Ahern; and his sister-in-law, Mary Ellen Ahern. He was also the beloved stepfather to Robert Dietter, Jr., Kristin Henderson, Craig Dietter, & John Dietter; devoted grandfather to Robert III, Tyler, Morgan, Brooke, Jaden, & Ian Dietter and Daniel, Caroline, & Kate Henderson, and loving uncle to many nieces & nephews. Predeceased by his siblings, Mary Rowe, Julia Willett, Margaret McMahon, Eileen Stackpole, James, Stephen, & Timothy Ahern. Bill was cherished by many close friends and was well-known for his wonderful sense of humor, his sharp intellect, charm, and generosity to all. He received his B.S. and M.S. from the University of New Haven. He was a Lieutenant in the New Haven Police Department, having served honorably for 25 years. After retiring from the police department he became Chief of Security at Quinnipiac University for 10 years. Bill's family would like to share their gratitude and appreciation to Franciscan Home Care for their unwavering support, compassion, and kindness. Funeral from BEECHER & BENNETT, 2300 Whitney Ave., Hamden on Monday, March 19th at 11:00 a.m., followed by a Mass of Christian Burial in Our Lady of Mt. Carmel Church at 11:30 a.m. Burial will take place in St. Mary's Cemetery. Friends are invited to visit with Bill's family on Sunday evening from 5:00 to 7:00 p.m. at the funeral home.