Bogus lottery winnings, sweepstakes fraud schemes, telemarketing scams, phony phone utility workers or messengers dropping off a bouquet of flowers for a neighbor - the list of more or less imaginative scams targeting senior citizens is long.

Imagine the following scenario: the phone rings, you pick up and the man on the other end identifies himself as a police officer.

The caller explains that there has been a rash of burglaries in your area. He feigns concern, asks whether you keep cash and valuables at home - and offers to safeguard them for you. A plainclothes officer is ready to pick them up at the door, he says.

Seniors are polite and trusting - and they believe in state institutions, so impersonating a police officer is an effective scam, warns Frank Scheulen, press spokesman for the State Office of Criminal Investigation (LKA) in North Rhine-Westphalia (NRW).

Eloquent callers

Citizens in the city of Cologne have reported 11 calls by scammers posing as police officers since Sunday - a "massive attack," a Cologne police spokesman told DW. They tell potential victims their names show up on a list carried by burglars caught in the area. The callers are so eloquent that in similar cases, seniors have handed over their entire savings.

The spokesman stressed that police never call people and ask them to hand over cash and that a call by real police never shows the emergency number on the display.  

Scammers are inventive, and come up with new angles all the time. In a rash of cases last year, they claimed to be agents from Germany's Federal Criminal Office (BKA) out to protect retirees from scammers.

Make victims feel safe

To boost their credibility, the criminals use a technology known as caller ID spoofing, which lets a display show a phone number different from that of the telephone from which the call is being placed - in this case, Germany's nationwide "110" police emergency number. The callers speak perfect German, but they aren't in Germany. Experts suspect they are holed up in call centers, perhaps somewhere in Turkey.

The authorities have been grappling with senior citizen fraud for decades, Scheulen told DW, adding that it's on the rise although the police constantly warn the elderly. Police believe there are quite a number of unreported cases because the victims are embarrassed at having fallen for the tricks.

More trusting, more prosperous

One variety that seems to work particularly well nationwide is posing as a grandchild who needs money.

In 2015, that trick alone was reported 4,112 times in NRW - in 254 cases, the scam succeeded, with damages amounting to 3.79 million euros ($4.1 million), up from 2,887 cases reported the previous year.

Don't fall for phone calls by alleged relatives or police officers telling dramatic stories, and never give strangers money or let them into your home, cautions Scheulen.