Rae Foley (aka Elinor Denniston, Dennis Allan, & Helen K. Maxwell)
MR. POTTER MYSTERY Series:

Death and Mr. Potter   '55 (aka The Peacock Is a Bird of Prey)
The Last Gamble   '56
Run For Your Life   '57
Where is Mary Bostwick?   '58 (aka Escape to Fear)...CHRISTMAS
Dangerous to Me   '59
It's Murder, Mr. Potter    '61 (aka Curtain Call)
Repent At Leisure    '62  (aka The Deadly Noose)
Back Door to Death    '63 (aka Nightmare Honeymoon)
Fatal Lady    '64
Call It Accident    '65
A Calculated Risk   '70

STAND ALONES:

No Tears for the Dead    '48 
The Girl from Nowhere     '49 
Bones of Contention    '50 (aka The Other Woman)    
The Hundredth Door    '50............................CHRISTMAS 
An Ape in Velvet    '51 (aka The Velvet Web)
Wake the Sleeping Wolf    '52 (aka Don’t Kill, My Love)
The Man in the Shadow   '53 
Dark Intent   '54 
Suffer a Witch    '65 
Scared to Death    '66 
Wild Night  1966 
Fear of a Stranger    '67 
The Shelton Conspiracy    '67 
Malice Domestic    '68 
Nightmare House    '68 
Girl on a High Wire    '69 
No Hiding Place    '69 
Ominous Star    '71 
This Woman Wanted    '71 
The First Mrs. Winston    '72 
Sleep Without Morning    '72 
Reckless Lady    '73 
Trust a Woman?    '73 
The Brownstone House   '74 (aka Murder by Bequest)  
One O’Clock at the Gotham    '74 
The Barclay Place    '75 
The Dark Hill    '75 
Put Out the Light    '76 
Where Helen Lies    '76 
The Girl Who Had Everything    '77 
The Slippery Step    '77 

Written as  Dennis Allan:
  
House of Treason    '36 
Brandon Is Missing    '40 
Born to Be Murdered    '45 
Dead to Rights    '46 

Written as Helen K. Maxwell:  
The Girl in a Mask    '71 
Leave It to Amanda    '72 
The Livingston Heirs    '73