He also served on a citizens advisory commission formed in 1993 to explore alternative methods for disposing of mustard gas at Aberdeen Proving Ground.
An article in The Baltimore Sun after Mr. Riley's election in 1998 detailed how his "rusty, 1951 Ford pickup hauled the Edgewood civic activist down miles of county roads" during the campaign.
"I remember knocking on one door, and a kid came out," Mr. Riley recalled in The Sun article. "I introduced myself, and when he went to tell his parents, I heard his dad say, 'Does he have his truck with him?' ...The truck turned out to be a great way for people to identify me.
"But you could be standing out here in a clown suit, and if you didn't know the issues, people weren't going to vote for you," he said.
The Morning Sun Newsletter
Get your morning news in your e-mail inbox. Get all the top news and sports from the baltimoresun.com.
"My mother lived in an area that had been heavily bombed, and I was born undernourished," he told The Sun.
The article said his mother and stepfather moved to Harford County in 1965, and Mr. Riley "came to enjoy the rolling hills and peacefulness of life in Harford. In 1973, he married, and he and his wife, Linda, settled into a house just outside the gates of the [Aberdeen Proving Ground's] Edgewood facility."
A memorial service will be held 2 p.m. Wednesday at the McComas Funeral Home in Abingdon, 1317 Cokesbury Road, according to the funeral home website.
In addition to his wife, he is survived by a daughter, Anna.