As time passed, Kearney greatly refined his "modus operandi", which enabled him to carry out his crimes much more efficiently and frequently. Starting in 1974, Kearney is estimated to have committed murders on an almost monthly basis. After picking up his victims along the freeway or at gay bars in his Volkswagen or in his truck, Kearney would typically shoot his victims in the temple above the ear with a Derringer .22 pistol in his right hand, while steering his car with his left hand and simultaneously monitoring the speed limit to minimize the predictability of the altercation and to avoid exhibiting any unusual behavior to potential witnesses. After murdering his victims, Kearney would leave the bodies slumped upright in the passenger seat and drive to a secluded area to sexually violate them.