“Skylarking” refers to someone engaged in horseplay. It could also describe a person who plays practical jokes or commits shenanigans. In this case, the constable shot the man for messing around. Willcox was indeed a tough Arizona town.
Marshall Trimble is Arizona’s official historian. His latest book is Wyatt Earp: Showdown at Tombstone. If you have a question, write:
Ask the Marshall, P.O. Box 8008, Cave Creek, AZ 85327 or e-mail him at firstname.lastname@example.org