Dennis P. Riordan

Dennis P. Riordan, 75, of Dedham, MA and Falmouth, MA, passed away on August 20, 2025.

While growing up in Westwood, MA, Dennis spent many memorable summers with his family at Peggotty Beach in Scituate, MA.

Born in Boston, MA, Dennis graduated from Xaverian Brothers High School in Westwood, MA and went on to earn his Bachelor of Science in Accounting from Boston College.  He began his law enforcement career as a patrolman with the Westwood (MA) Police Department before advancing to serve as a Lieutenant with the Massachusetts State Police. His dedication to public service then brought him to the United States Drug Enforcement Administration (DEA), where he worked on both domestic and international drug enforcement efforts. Dennis also played an important role in INTERPOL, collaborating with police organizations across 195 member countries.  He was deeply proud of his service where he placed his life on the line to protect his community, and he forged lifelong friendships along the way.

Beyond his professional life, Dennis will be remembered for his love of going to the pond in Falmouth.  He enjoyed photography, golf and the sunshine of Florida. He lit up every time one of the kids had updates on what they were up to or any of their achievements.  He is remembered as always being ready and willing to help a friend.  He was the first to volunteer to drive anyone to an appointment or provide resources and housing for those in need.  He participated in town politics in Falmouth and enjoyed Xaverian and St. Sebastians football and lacrosse teams. As one of his nieces said, “Uncle D was the best!”.  He has left a lasting mark on all who knew him.

Dennis is survived by his sister, Paula M. King of Plainville, MA and his brother, John J. Riordan (Pam) of Franklin. He leaves behind his beloved daughter Mary Ellen Riordan of Lynn, MA, and a son, Sean Lovely and daughter Erin Jackson, both of Franklin.  He also leaves behind his cherished nieces and nephews who brought him immense pride: Cynthia (John) Driscoll of Leominster, MA; Brenda Sansone (Joseph) of Mansfield, MA; Christopher (Heather) King of Greenwood, IN; Christopher (Erika) Riordan of Leesburg, VA and Andrew (Kellie) Riordan of Deerfield, NH and his precious grand-nieces and nephews Abigail, Dylan, Hannah, Emily, Tyler, Fiona, Henry, Wilma and Marilyn.

Visiting hours will be held on Monday, August 25, 2025, from 4-7 p.m. at Robert J. Lawler & Crosby Funeral Home, 1803 Centre Street, West Roxbury, MA. A Rite of Christian Burial will be celebrated on Tuesday, August 26, 2025, at 10 a.m. at Holy Name Parish, 1689 Centre Street, West Roxbury MA.  Burial will be in St. Joseph’s Cemetery in West Roxbury, MA. 

Attendees are kindly asked to bring a note with a memory they have of Dennis to be gathered as a keepsake for the family.

Memorial contributions in Dennis’s name may be made to the Tunnel to Towers Foundation, 2361 Hylan Boulevard, Staten Island, NY 10306 or Hillsdale College, 33 E College St, Hillsdale, MI 49242.