Eislingen, Germany  - Two teenagers have been indicted for the murder of four members of a family in south-west Germany in April, prosecutors said on Friday.

The 18-year-old son of the murdered family and his 19-year-old friend are accused of having gunned down the parents and two sisters out of greed, state prosecutors said in the town of Ulm.

The older of the two teens, who are both in custody, has confessed his part in the murders and heavily implicated his friend. The son has only confessed to a prison employee.

The prosecution statement says the 18-year-old wanted to move out of his parents' home but lacked the money to do so. In February his mother had given him access to an account with a six-figure balance.

This allegedly prompted him to kill his family and inherit the money, the statement read.

Police said the duo behaved like professional killers. They allegedly first shot dead the two sisters, aged 24 and 22, who were watching television while their parents were in a local restaurant with friends.

They then went to the restaurant themselves and joined the parents, returning to the apartment an hour later to wait for the couple, aged 57 and 55, to come back.

An hour later, in the early hours of April 10, they shot dead the two adults in the hallway of the flat, police said.

The killings were reported to police by 18-year-old, who said he found the bodies of his family when he returned home after spending the night with his friend.

Police immediately suspected a family member or someone with close links to the family because there were no traces of a break-in and the flat was not ransacked. (dpa)