The original 1958 investigation quickly focused on several groups of individuals. According to the investigators' case notes, the list of suspects was eventually narrowed to the following:
The men in this group are toughs prone to heavy drinking and violence. All have prior arrests for assault and public disturbance, drunk and disorderly conduct individually and as a group.
Danahy (considered the leader and instigator of this group) has a long history of romantic attachment to Lisa Izard and harassment of the Izard family
Danahy may have taken the opportunity of the layoffs at Bowlan to conspire with one or more of this group in the murder of Richard Izard. It is believed that Lisa Izard was not a target of this attack.
All of the following are Bowlan employees, all are between the ages of 25 and 29 years (1958), and all have been friends since childhood.
Harvey Booker, Pete Corey, Jessie Danahy, Jack Peach, Jeff Skinner, Frank Valenti
Suspects not cleared from this group: Harvey Booker, Pete Corey, Jessie Danahy
Elroy Murphy — the last person known to see missing child Ricky Izard. Murphy was considered and cleared.
Thomas Joe Hinkley — considered as a potential conspirator with his brother, Walter Hinkley. Some suspicion was attached to his finding the bodies and his manner in interviews. Thomas Joe Hinkley has been cleared.
The following Bowlan employees are considered low on the suspect list. However, they have no verifiable alibi for the time of the murders, they showed some indication for suspicion in their interviews or actions, and they cannot be removed from consideration:
Nathan Buck, Earl Long