Baltimore Ravens wide receiver Zay Flowers is under investigation for domestic assault, according to multiple reports. Baltimore County police are probing a Jan. 21 incident in the northern suburb Owings Mills, Md., the Baltimore Banner reported Thursday. The investigation also involves a police department in the west Boston suburb of Acton, Mass., according to the outlet. Neither police department publicly released details of the investigation. Flowers has not been charged with any crimes. The day before the reported incident, the Ravens defeated the Houston Texans in the AFC playoffs. The ne…