I just don't understand it if I'm honest. So, he thought there was an intruder in the house, grabbed a gun, didn't check where his partner was, and shot four times? How does that make any sense?! If I heard a strange noise in the house, I'd first turn to my husband in bed, if he wasn't there, I'd assume he was the one making the noise! If I wasn't sure, I'm pretty sure I'd say 'darling, is that you?', pretty sure I wouldn't grab a gun, shoot through the door four times just in case it wasn't DH after all and was in fact an intruder.
How is he not behind bars?!