half hour dramatic home security camera video capturing a life-or-death struggle. A biotech executive violently attacking his brother-in-law before police say he shot him and just hours after he... See More
half hour dramatic home security camera video capturing a life-or-death struggle. A biotech executive violently attacking his brother-in-law before police say he shot him and just hours after he opened fire on an ex-business partner. Abc's linsey davis is here with more on that. Good morning, linsey. Good morning, robin. During monday's prelimiry hearing, we heard testimony from hans peterson's girlfriend who describes him as agitated and focused as he worked on his computer after midnight the morning of attacks. She said he had been drinking and some some convincing to go to bed but when she woke up he was gone. The final moments of 49-year-old hans peterson's alleged bizarre shooting spree the night of september 18th caught on tape. Watch as this surveillance video captures the once successful biotech executive gun in hand breaking into the home of ron fletcher, his former brother-in-law, off camera fletcher says peterson found him in his bathroom and a struggle ensues. Fletcher telling his kids to lock their doors and call 911. Bullets fly. When I grabbed the gun he fired and shot me in the stomach and I tackled him to the ground and fought, fought with him. Reporter: In pain and holding his stomach fletcher says he manages to keep the gun away from peterson fighting him off. When he reaches for his cell phone to call 911, he says peterson stops him by smashing his phone. He started yelling at me to open my safe. I'm going to kill you. Open your safe. Reporter: Peterson's alleged rampage continues until police arrive guns drawn. Finally putting an end to a shooting spree that allegedly started four hours earlier anyone half a mile away. Earlier that night, peterson allegedly broke into the home of this man, steven dowdy his former business associate. Prosecutors accuse peterson of firing into dowdy's bedroom while he and his wife were sleeping. I realized then that this is not merely a robbery but this is someone trying to assassinate me. Reporter: Dowdy was shot in the back and says he would have died had he not taken cover behind his dresser where four bullets were lodged. When the bullets stopped firing and I was concerned that he was trying to reload, that's when I opened the curtains to look and see a little bit. I was afraid, of course, he would shoot me in the head right there. Reporter: According to court documents peterson's estranged wife says her husband went into an emotional tailspin and depression after he lost his job. I would not be sitting here today if not. Reporter: He began to change when he stopped taking medication prescribed to him after a skydiving incident. He not only lost his job but was going through a messy divorce. If convicted he faces up to 96 years in prison. He has pleaded not guilty to premeditated attempted murder among other charges but that surveillance video, I imagine, will be hard to explain. That will be played in court hard to explain. Linsey, thank you.
This transcript has been automatically generated and may not be 100% accurate.