Dempsey's spy series "Pulsar" (co-written with Robin Moore), contains the books The London Connection and The Italian Connection. They feature the main character Tim Kyle, the lead agent for the security corporation Pulsar International. Kyle is notable among spy novel protagonists for being happily married with children and relying largely on his "computer-like" brain to solve cases. 
The London Connection: Pulsar No. 1, (co-written with Robin Moore) Severn House, 1980
The Italian Connection: Pulsar No. 2, (co-written with Robin Moore) Severn House, 1981
Miss Finney Kills Now and Then, Tom Doherty Associates, LLC, 1982
The Stendal Raid, Critics Choice Paperbacks/Lorevan Publishing, Inc., 1985, ISBN 0-931773-17-2
Copper, Tom Doherty Associates, LLC, 1989. Story of Butte, Montana, in the 1880s. Butte was the site of a large copper mine, and the entrepreneurs known as the Copper Kings.
What Law There Was, Tom Doherty Associates, LLC, 1991, ISBN 0-312-85113-8. Based on a true story, this novel of the gold rush in Montana covers the rise of an organized crime gang called the "Innocents", led by sheriff Henry Plumber. The Innocents robbed, murdered and terrorized the community until an organized vigilante group attacked them with late-night visits and anonymous hangings.