Don Pendleton
Joe Copp, a private investigator in Hollywood, California:

Copp for Hire (1987)

Copp on Fire (1988)

Copp in Deep (1989)

Copp in the Dark (1990)

Copp on Ice (1991)

Copp in Shock (1992)

Aston Ford, a former naval intelligence officer, now psychic private investigator:

Ashes to Ashes (1986)

Eye to Eye (1986)

Mind to Mind (1987)

Life to Life (1987)

Heart to Heart (1987)

Time to Time (1988)