A former Albuquerque police officer standing trial on a second-degree murder charge in the shooting death of a homeless camper will testify in his own defense for a second day Wednesday.

Dominique Perez was one of nearly 20 officers to respond to a 2014 police standoff with James Boyd — who suffered from paranoid schizophrenia and pulled knives on two officers who were first to respond to reports of his illegal campsite.

Perez told jurors Tuesday that he opened fire because a K-9 officer who did not have a weapon in hand appeared to come within arms’ reach of Boyd and his knives. Perez was standing downslope from the K-9 officer and Boyd during the standoff in the Sandia Mountain foothills.

An analysis later determined that the K-9 handler was roughly 9 feet from Boyd.