A call from this Los Angeles cell number arrived today. When the call rolled to voice mail, the caller left no message, just dead space. This is typical of robocallers (unlawful telemarketers) who use automated dialers to troll the phone lines in search of gullible schmucks.
Of course, there is a possibility (however slight) this was a "wrong number" call. Still, it's best to let the answering machine to take calls from unfamiliar or suspicious numbers.