HEFEI, China — The murder trial of Gu Kailai, the wife of the deposed political leader Bo Xilai, began here on Thursday morning and came to an end seven hours later, with officials saying that the defendant and an accomplice had all but confessed to poisoning a British businessman who had threatened the safety of Ms. Gu’s son.


In a statement read to foreign journalists, the deputy director of the Hefei Intermediate People’s Court placed most of the blame on Ms. Gu, 53, saying she gave the Briton, Neil Heywood, a fatal dose of poison as they sat in a hotel room in Chongqing, the metropolis in southwest China that was run by her husband until his downfall last spring.


“The criminal facts are clear; the evidence is solid,” the court official, Tang Yigan, said.


A verdict will be announced at a later time.


According to the statement, the killing took place on the evening of Nov. 13 after Ms. Gu and Mr. Heywood spent time drinking together at a rented villa on the outskirts of the city. After consuming some tea and alcohol, Mr. Heywood began to vomit and asked for a glass of water, at which point Ms. Gu “poured poison into his mouth,” the court said. The statement said the poison was prepared in advance and given to the family employee, Zhang Xiaojun, 33, who had accompanied Mr. Heywood to Chongqing from his home in Beijing.


The court provided no further detail of Mr. Zhang’s role, nor did it specify who prepared the poison.


Mr. Tang also said Mr. Heywood deserved some responsibility for the murder because he had threatened the safety of Ms. Gu’s son, Bo Guagua, a recent graduate of the John F. Kennedy School of Government at Harvard. He did not elaborate on the nature of the threat.


Analysts believe the mitigating circumstances presented by the court — that Ms. Gu feared for the safety of her son — lessened the likelihood that Ms. Gu would face the death penalty.


Mr. Tang, the court official, also portrayed Ms. Gu as emotionally frail.


He quoted her lawyers as saying Ms. Gu’s “ability to control her own behavior was weaker than a normal person.” The lawyers, he added, said they hoped for leniency given that she had assisted the authorities by revealing details about other people’s crimes.


The court’s statement raised a host of questions: it did not explain the “economic interests” that had prompted the dispute between Ms. Gu and Mr. Heywood, 41, an enigmatic figure and longtime friend. It also avoided any mention of her husband, who reportedly knew about his wife’s crime and sought to cover it up.


One Chinese journalist who spoke to people who attended the trial said Mr. Bo’s name came up only once, in a reference to Mr. Zhang as a family employee.


The trial’s brevity suggests that Chinese leaders are eager to bring to a close an embarrassing scandal, one that strained Chinese-British relations and complicated an upcoming leadership transition scheduled for the fall.


The British Embassy had no immediate comment on the trial. The choice of the venue — in China’s eastern Anhui Province, hundreds of miles from the scene of the crime — highlighted the extent to which Communist Party leaders were seeking to minimize anything surprising, however unlikely, that might arise during the painstakingly orchestrated trial. Legal analysts say distance was not the only factor in choosing the provincial capital of  Anhui: the president of the Supreme People’s Court, Wang Shengjun, has deep ties to the province, all but guaranteeing a compliant court. President Hu Jintao  also comes from Anhui,  as does Vice Premier Li Keqiang, the man presumed to be the future premier.


“This trial is the outcome of a political struggle,” said Pu Zhiqiang, a prominent defense lawyer, referring to powerful enemies of Mr. Bo, a brash up-and-coming politician who alienated many party luminaries. “Any trial to which the central party pays this much attention had no chance of being fair.”