A man suspected of killing six people in a shooting spree in Shanghai on June 22 that shocked the nation stood trial on five charges on Monday.

Fan Jieming, the 62-year-old suspect who is accused of intentional homicide, robbery, robbery of firearms and illegal trade and possession of firearms and ammunition, told Shanghai No 2 Intermediate Court the killings were because he had lost face in the factory where most of the shootings took place.

The prosecution said police confiscated a shotgun, a rifle and three air rifles when they captured Fan at the Shanghai Guangyu Fine Chemical Co, where the boss Li Zhizhong and three employees were killed on the night of June 22. Fan's brutal personal grudge led to the death of six people and injuries to another four, they added.

Guangyu, a private chemical factory located in suburban Baoshan district, was established in 2001 by Li. In 2011, nearly half of the business was sold to Fan Guofu, who asked his uncle Fan Jieming to become office director of the enterprise.

Li and Fan Jieming and their followers were entangled in unending disputes and some of the victims had "caused trouble to my management of the factory", Fan Jieming said.

"They broke the locks of the warehouses and changed the locks of the factory's two gates so that our trucks couldn't enter," Fan Jieming, a Shanghai native who once served in the military, told the court.

"I didn't fight with them for money. I'm an employee and don't have any ownership of the company's property," he said.

Fan Jieming met Zhang Yunfeng, who worked for Li, in the factory at around 3 pm on June 22. Fan became infuriated when he saw some valuable stainless steel had been removed from the warehouse by Zhang's team. He sprayed sulfuric acid stored in the warehouse on Zhang's face and beat him to death with an iron pipe.

"I don't agree with the prosecutors. I didn't plan to kill him, and it was caused by a sudden impulse," Fan Jieming said in his defense.

He then retrieved a shotgun and bullets from the factory dorm and drove to his ex-wife's home.

He intended to flee to his sister's home in Anhui province, he said, but wanted to collect a suitcase from his ex-wife's home in which he had three air rifles to keep him safe.

He then took an unlicensed cab to the Zhoupu area of Pudong as he knew it was secluded.

He planned to make the driver, named Bian, give up his car so Fan could drive to Anhui.

"But when I asked him to go away and leave the car for me, he said he wasn't frightened by a gun replica, so I shot him," Fan said.

"My head exploded at the moment he fell down. I could find a reason for killing Zhang, but couldn't find one for killing the driver. I stood there for two or three minutes, and then fled" in the car, he said.

"As I was driving, I thought, 'now that I've killed people, why not go back to kill Zhang, who caused most of the troubles in the factory?'" he said.

A second man surnamed Zhang also worked for Li, and Fan claimed he had stolen much of the factory equipment.

Fan drove back to Baoshan where he shot two sentries at a naval base, killing one, to obtain another rifle. He then shot at least five more people, killing three including Li, after returning to the factory at around 11 pm.

"I didn't even see who the two sitting in the guard room were. When I looked into the room, they stood up. I was very tense then, so I fired the rifle," Fan said.

He was detained shortly after and the weapons were seized. The guns and bullets were bought in 2000, Fan said.

Fan expressed his regret and apologized to the victims' families during the trial.

The court will issue its verdict at a later date.

zhouwenting@chinadaily.com.cn