By An Baijie

A serial killer who, along with accomplices, murdered 13 people including three policemen and two children in 10 separate cases between 1996 and 2005 was sentenced to death in Guangdong Province on Sunday.

The mass murderer also raped a junior high school girl, and stole 288,610 yuan ($42,000).

Cheng Ruilong, 37, admitted to the Foshan Intermediate People's Court that he was guilty of murder, robbery, and rape in 10 cases in six provinces, according to the Xinhua News Agency.

In January 2005, Cheng was arrested in Jiangxi Province on a robbery charge while using the alias, "Zhou Quan." The local court sentenced him to seven years in prison for robbery.

In 2009, while investigating another of his crimes, police identified "Zhou Quan" by his real name, Cheng Ruilong.

Cheng told reporters that he was not cruel. He bragged that he could have murdered over 130 people, but "just" killed 13, the Guangzhou Daily said.

Cheng smiled when he stepped into the Foshan court Sunday, and even wished "Happy Spring Festival" to the judge, the paper reported.

In 1996, Cheng and three accomplices broke into a residential building in Foshan, Guangdong, and robbed people of 23,400 yuan ($3,400) and HK$ 10,140 ($1,300), the Legal Daily reported.

One of the robbery suspects was shot dead while escaping, and the other two accomplices were arrested in 1998.

Cheng said that on the morning of Mid-Autumn Day, 1997, he killed a man and his wife because the couple resisted his attempt to rob them, according to the Guangdong-based Information Times.

Cheng stabbed the man 25 times and then stabbed the man's wife in the stomach, even twisting the blade several times while the knife was stuck in her belly.

Cheng clearly recalled the details of his confrontations with the police, but said he couldn't remember his mother's name because he had lived under so many different aliases, according to Guangzhou Daily.

In 1998, when two patrolmen in Foshan asked Cheng to produce his ID card, the suspect drew a pistol from his belt and shot the two officers dead.

"I had killed many people before and if the two policemen knew who I was, I would be dead. So I killed them," he said.

Cheng said that in 1998, he was trapped by dozens of armed policemen in Guilin, the Guangxi Zhuang Autonomous Region. He said he managed to escape by pretending to be a cleaner and shooting a police officer dead, according to the Xiaoxiang Morning Post.

Cheng, the father of a junior high school boy, said that while in detention he tried to meet with his son, according to the Information Times.

Cheng's wife said that Cheng had not contacted his son for more than 10 years and that she never let her son know that his father was a murderer.