question:  Why did Frank make a phone call after shooting the client at the beginning of the story?
context: Frank Pembroke sat behind the desk of his shabby little office over Lemark's Liquors in downtown Los Angeles and waited for his first customer. Therefore, it was with a mingled sense of excitement and satisfaction that he greeted the tall, dark, smooth-faced figure that came up the stairs and into the office shortly before noon. Opening the desk drawer, which was almost empty, Pembroke removed an automatic pistol fitted with a silencer. Pointing it at the amazed customer, he fired four .22 caliber longs into the narrow chest. The series of events leading up to Pembroke's present occupation had commenced on a dismal, overcast evening in the South Pacific a year earlier. Standing on the forward deck, Pembroke was one of the first to perceive the peculiar odor and to spot the immense gray hulk wallowing in the murky distance. Then the explosion had come, from far below the waterline, and the decks were awash with frantic crewmen, officers, and the handful of passengers. Lacking such loyalties, Pembroke adapted quickly to the situation in which he found himself when he regained consciousness. The wallet in his pocket contained exactly what it should, approximately three hundred dollars. One in particular, an attractive woman of about thirty, tossed back her long, chestnut locks and gazed up intently at Pembroke as he passed. "You're not casual enough, for one thing," said Pembroke, deciding to play along with her for the moment. "Incidentally, just where are we, anyway? But as he left the shop he began checking off every west coast state, city, town, and inlet. "Which way is it to San Francisco?" asked Pembroke. Pembroke watched him hurry off to service a car with a sense of having been given the runaround. To his surprise, the boy came back a few minutes later after servicing the automobile. "All cargo ships, I'll bet. No passengers," said Pembroke. Going to the bar, he recognized one of the Elena Mia's paying passengers.
output:  He wanted a call in a third party to take a look at his client.
options:  He needed to report the shooting to the police.  He wanted a call in a third party to take a look at his client.  He wanted to tell his partner that his newspaper at had worked.  He promised those in charge of him that he would report back every time he successfully made a kill.