Police are investigating why Dallas plaintiffs lawyer Michael Edward “Mike” Schmidt opened fire on them on Jan. 2, prompting officers to return fire that fatally wounded the attorney in his residence, according to an initial statement by the Dallas Police Department.

Schmidt’s father, attorney C.L. Michael Schmidt, was heading back to Dallas from Santa Fe, N.M., after learning of the shooting on Jan. 2, Texas Lawyer’s press time. He said he knows little about the incident or what may have caused it.