LOS ANGELES - TWO women in their 70s befriended and then murdered homeless men in an effort to collect millions of dollars in life insurance, a Los Angeles court heard on Tuesday.

Helen Golay, 77, and Olga Rutterschmidt, 75, have been dubbed the 'Black Widows' by local media for allegedly orchestrating a scheme that saw them take out insurance policies on destitute men before killing them.

The two women received nearly US$3 million (S$4.13 million) in insurance payouts before their crimes were discovered, prosecutors said at the start of their trial at Los Angeles Superior Court.

Golay and Rutterschmidt are charged with two counts each of murder and conspiracy in the deaths of Mr Kenneth McDavid and Mr Paul Vados.

Mr McDavid, 50, was found dead in an alley in Westwood in June 2005. He had been run over by a car. Mr Vados, 73, was killed after being run over in an alley in Hollywood in 1999.

Prosecutors said last year that they would not seek the death penalty against either of the defendants, who face life in prison without the possibility of parole if convicted of murder.

Prosecutor Do said Golay and Rutterschmidt specifically targeted homeless men, took out insurance policies on them and claimed they were related to the victims. According to the prosecutor, the women applied for 26 life insurance policies on three different people - including the two dead men.

The women knew there was a loophole in California law that prevented insurance companies from challenging policies that had been in place for more than two years, Mr Do said.

'The only way they were going to get paid is if they waited two years ... with murder on their mind each of those days,' Mr Do said, alleging that the women collected US$2.2 million when Mr McDavid died and US$600,000 when Mr Vados was killed.

'They made a profit of 2.8 million on the lives of men who were homeless and destitute,' Mr Do said, noting that the men were 'forgotten' people, so no relatives were likely to come forward to contest the insurance policies.

Prosecutors said Golay was believed to have been at the wheel of the car that ran over Mr McDavid three years ago.

'The victim would always be run over - crushed to death - in an alley with no witnesses ... it always looked like it was a hit-and-run accident,' Mr Do said.

Golay and Rutterschmidt have been in jail without bail since their arrest.

Later on Tuesday, prosecutors played jurors excerpts from a surreptiously recorded conversation between the two women shortly after their arrest where Rutterschmidt told Golay: 'You were greedy. That's the problem.' Golay then tells Rutterschmidt: 'Be quiet. Don't say anything.'