On May 30, 1615 (the fourth day of May, the 43rd year of Wanli of the Ming Dynasty), a Suzhou man Zhang Cha broke into the Ciqing Palace where Crown Prince Zhu Changluo lived with a date wooden stick. He beat him as soon as he entered the door and injured the gatekeeper eunuch Li Jian. After rushing to the corridor in front of the hall, he was captured and handed over to the Donghua Gate guard Zhu Xiong to command him to put him under arrest.

The next day, when the Crown Prince heard the report according to the facts, he ordered Liu Tingyuan, the censor of the city to inquire impartially. Liu Tingyuan proposed a wanted criminal and interrogated him on the spot, revealing that the eunuchs Pang Bao and Liu Cheng under Zheng Guifei were the mastermind. When the chief of the Ministry of Punishment was appointed to the throne, the Donglin Party exposed and found out Zhang Cha's prison situation. During the court discussion, He Shijin and others of the Donglin Party advised the matter to investigate the mastermind; non-Donglin Party University Tufang Congzhe and others advocated punishment for madness.

At that time, some people suspected that Zheng Guifei colluded with her brother Zheng Guotai to murder the Crown Prince. After Shenzong learned about this, he summoned Grand Scholar Fang Congzhe, Wu Daonan and various civil and military ministers in Cining Palace and said: Don't alienate him and the Crown Prince, which means that neither he nor the Crown Prince are willing to delve into this matter.

On June 24, Zhang Cha was executed for the crime of being a mad traitor, and Pang Bao and Liu Cheng were killed in the inner court. The "assault case" was ended.

Comment: Due to the east window incident, Concubine Zheng instigated the sling incident, which greatly weakened his power, but instead consolidated the position of Prince Zhu Changluo.