In his later years, Crooks gained notice as a perceived judicial moderate and swing vote on a court otherwise divided into two ideological blocs.

[1] From 1963 to 1966, Crooks served as an officer in the United States Army, assigned to the Judge Advocate General's Corps in the Pentagon.

[3] Although appointed by Schreiber, Crooks ran for the Wisconsin Supreme Court in 1995 as a conservative; his campaign was directed by Scott Jensen, a prominent Republican legislator later convicted of criminal ethics violations.

His participation in decisions lifting a medical malpractice damages cap and permitting a lawsuit against lead paint manufacturers disassociated him from the court's conservative bloc.

[11][12] In April 2015, Crooks broke from both Abrahamson and the conservative majority in a dispute over the election of Patience Drake Roggensack as the court's chief justice.

He was a director of the Notre Dame Law Association and a member of the James E. Doyle Chapter of the American Inns of Court.