David Pacel‑Sellers (also known as Dave), age 69, of Sun City Center, Florida, passed away on Monday, January 12th, 2026, due to complications of pneumonia. He was surrounded by his loving family. He will be deeply missed.

Dave was born on July 3rd in Washington, DC, to Thomas and Mildred Pacl. He grew up in Greenbelt, MD, where he attended Parkdale Senior High School. From a young age, he enjoyed taking things apart to discover how they worked. His curious mind led him to a lifelong passion for fixing, modifying, and improving everything he touched, from electronics to cars. He also enjoyed camping and hiking with his little sister Karen and his Pacl cousins.

He went on to attend McMurry University in Abilene, Texas, and the University of Maryland, College Park, earning his bachelor's degree in 1981.

Dave founded PSI Information Technology Consulting in 1998 and served as its president and CEO until his retirement. During his 28‑year career, he worked on the forerunner of the Internet (DARPA net), as well as several versions of the TCP/IP protocol. He was Senior Program Manager at Telecommunication Systems, Inc. (TCS) in Annapolis, MD, and Technical Director for Kestrel Associates in Falls Church, VA. He also worked for CSI, Compuware, and Litton/Amecom.

Outside of work, Dave coached the Boys & Girls Club baseball team in Upper Marlboro, MD, from 1989 to 1994. In addition, he advocated for the civil and human rights of adults adopted as children. For several years prior to retirement, he poured his energy into revitalizing neglected properties, turning them into sturdy, hopeful starter homes for families beginning their journeys.

Friends and family remember him for his lively personality, his sense of humor, and his unique perspective. His vast, inventive vocabulary and gift for storytelling made every conversation memorable. He brought warmth and wit to every room he entered, leaving people feeling seen, heard, and always laughing. He adored his children and his spouse, Darlene, and he cherished time spent with friends, the water, boats, beaches, music, the arts, and travel.

He is survived by his partner of 24 years, Darlene Kavanaugh; his son, James Pacel; and his daughter, Elizabeth Allen; as well as their significant others, Angelina Allerton and Ryan Allen. He also leaves behind his cousins Jeff Pacl, Dennis Pacl, Tim Pacl, Peggy Sisson, and Michael Patrick McIntyre, and their families. He was preceded in death by his cousin Michael Pacl; his parents, Tom and Millie; and his younger sister, Karen.

A Private Celebration of Life will be held on Sunday, February 15th.