The attack was carried out by members of a gang called the Mongolian Boys Society in retaliation for the murder of Randy Xiong, the brother of a gang member, Fresno
police Department Chief Andy Hall told a news conference.
The gunmen made their way into the yard through an unlocked gate and began firing with semi-automatic pistols shortly before 8 p.m. on Nov. 17, killing Xy Lee, Phia Vang, Kou Xiong, and Kalaxang Thao, police said.
A string of tips led to the arrest of suspect Billy Xiong on Dec. 17 for mail theft and, during a search of his vehicle, police found a Glock 9mm semi-automatic handgun.