An investigation into an assaulted infant led to the discovery of 21 surrogate children. This finding resulted in the arrest of Guojon Xuan and Sylvia Zhang. The couple was taken into custody after police found the large number of surrogate children.

Further details about the case are available from the source. The investigation and arrests were part of a larger inquiry into the welfare of the children.

The couple's arrest followed the initial investigation into the assaulted infant, which ultimately led to the discovery of the 21 surrogate children.