The defense attorney for Steven P. Osburn, 24, an Army veteran who is accused of killing his friend, 23-year-old Zachary S. Gallenberg, in a south Waukesha neighborhood said Friday that the evidence will not support a mental-based plea of not guilty in the crime.

"I had to check it out because it is a unique situation with the victim and the defendant being best friends and (being in) combat," Boyle said in court.

Although the plea is not sustainable, Boyle said he intends to bring up the post-traumatic stress disorder issue during the trial. Boyle also alluded to self defense being pursued.

Boyle said during the hearing that he will not contest the facts during the trial. The trial is set for June 6.

Additionally, Waukesha County Judge Mark Gundrum, who went to high school with Gallenberg's stepmother in the 1980s, did not step down from the bench after prosecuting and defense attorneys indicated they had no issue with Gundrum proceeding in the case.

"We have not had much interaction of any kind in 20 years," Gundrum said.

Gundrum said he won't recuse himself every time a former high school classmate of his is connected to a case.

Boyle said he prefers Gundrum to proceed over the case, especially because of Gundrum's familiarity with the military.

According to the complaint:

A witness to the shooting told Waukesha Police Department officers that she, Gallenberg and Osburn had consumed some alcohol during the night of Aug. 5. Osburn and Gallenberg were arguing about their different branches of the military throughout the night.

The woman told investigators at one point in the evening, Osburn began choking her before going into his bedroom and then outside. Gallenberg eventually followed, she told police, and tried to give Osburn a bear hug, which is when Osburn took out a gun and shot Gallenberg.

In the meantime, police officers were on their way to the residence because Osburn called 911 and said if they did not respond, he would kill someone. One of the officers was approaching the residence when he heard the gunshot sound. Other officers were approaching the building at the same time. One officer reported turning the corner of the building, seeing Osburn, hearing yelling and then seeing the muzzle flash.

Osburn admitted several times to officers that he had shot Gallenberg.

“It bothers me that I shot Zach because he was my best friend, but I was threatened,” Osburn told police.

Gallenberg was transported to Waukesha Memorial Hospital where he was pronounced deceased at 4:47 a.m. Aug. 6.