“As in other cases in Stockton he ranted about needing money but ignored cash when it was right in front of him. What he wanted was items of personal value from those he violated: engraved wedding bands, driver’s licenses, souvenir coins.” 

One of the key characteristics of the GSK’s crimes is that the killer would often steal items of sentimental value from his victims. Though the GSK would tell his victims that he needed cash, he typically stole items that might be emotionally important to his victims while leaving behind cash or objects that might be worth more in terms of monetary value. The GSK’s interest in these objects suggests that he was motivated less by monetary needs than by deeper psychological complexes. 

“It’s a tiny minority of criminals, maybe 5 percent, who present the biggest challenge—the ones whose crimes reveal preplanning and unremorseful rage. Manuela’s murder had all the hallmarks of this last type. There were the ligatures, and their removal. The ferocity of her head wounds. The several-month lapse between appearances of the sole with small circles suggested the slithering of someone rigidly watchful whose brutality and schedule only he knew.” 

McNamara notes that aspects of the GSK’s murder of Manuela Witthuhn reveal the GSK to be a particularly rare breed of criminal. While most murders can be traced to an individual personally connected to the victim, the GSK’s brutality and careful planning suggest that he belongs to the smaller group of criminals who murder individuals unknown to them. 

“The truth, of course, was much weirder: I was foregoing a fancy Hollywood party to return not to my sleeping infant but my laptop, to excavate through the night in search of information about a man I’d never met, who’d murdered people I didn’t know.” 

McNamara relates a story of how she and her husband, Patton Oswalt, leave a movie premiere early so that she can read up on breaking news of the arrest of a criminal she had been investigating. The anecdote displays McNamara’s single-minded obsession with investigating unsolved murders.