Starved of company, having not seen their adult children for some time and with the nearest neighbor's house 50 meters away, the lonely couple, who apparently saw no reason to doubt Chen's story, cooked a large meal and invited him to eat with them.

Sun and his wife were robbed and murdered later that same evening, but their bodies went undiscovered for a day and a half. Sun's niece, Sun Rong, who also lives in the county received a call and rushed to her home village, where she discovered that her parents-in-law had also been murdered, according to Huashang, a local daily newspaper in Xi'an, the capital of Shaanxi province.

When Chen was apprehended, he confessed that he had killed the four seniors on the same day. He also admitted killing the three other elderly residents in a nearby village a week or so earlier.

Very few young people live in Heigou village, the population of which mainly consists of seniors and infants. The young have moved away in search of work and few of them can afford to provide food and lodging for their elderly parents in their adopted home towns, while the older children live in the local town where they attend school. That means approximately 30 households in the village consist exclusively of seniors, according to the village leader Weng Liancheng.

The case has highlighted the reality of life for "left-behind seniors" - a phrase used to describe rural dwellers aged around 60 or older, whose children have moved to the urban areas - many of whom live alone, eat alone and rarely receive phone calls or messages from their departed offspring.

Some have no idea where their children are. For example, Cheng Deguang, 80, only knows that his two sons are still alive. "They have their own lives and the burden has already been so heavy for them," he said. "I don't expect them to do more for me."

His younger son has not been home for spring festival for some years. Cheng's voice softened slightly on the other end of phone when he spoke about the boy, but still supports the idea that young people should go out to live their own lives.

Rural versus urban

There is an obvious disparity between the elderly in urban and rural areas. Those dwelling in urban areas can usually rely on their children for support, both in terms of finances and accommodation. The rural elderly are often not so fortunate. Some receive financial help from their children, but despite recent improvements in the social support system, some are struggling and live close to the poverty line, barely able to survive on an annual income of 2,300 yuan ($374).

"Left-behind seniors are one of the most disadvantaged groups in society. Sometimes they lack security awareness and usually have little understanding of the law or their rights," said Wang Junwen, a professor at the school of humanities and social sciences at East China Jiaotong University.

The left-behind seniors are usually poorly educated and reliant on handouts from their children. Moreover, the age demographic in many villages resembles an inverted pyramid, whereby the oldest residents are in the majority, according to Wang.