. >> reporter: lindsay patterson was on leave from her i.t. job in the navy, visiting her mom, who lives just over the back yard wall from the hall house. lindsay was inside, in the bathroom that faced away from the hall house and out onto the street, when she heard a noise. >> it was a horrible scream. it was this -- something is wrong kind of scream. >> reporter: a woman's, she thought? she went outside to tell her mom. >> and i said, "did you hear that scream?" and she said, "yeah, but i think it's just kids playing in the -- playing in the pool." >> reporter: kids? at 6:00 something in the morning? lindsay walked over to the six-foot brick wall between their yard and the halls'. she stepped on the planter, she said, and looked over the wall. >> at that point i saw a man with his hands -- one hand on top of a woman's head and then one hand on her back. and she was face down in the water. >> like something was going on? >> yeah. that's what i assumed. >> reporter: that is, she thought she was looking at a sex act in progress. >> i don't know

. >> reporter: lindsay patterson was on leave from her i.t. job in the navy, visiting her mom, who lives just over the back yard wall from the hall house. lindsay was inside, in the bathroom that faced away from the hall house and out onto the street, when she heard a noise. >> it was a horrible scream. it was this -- something is wrong kind of scream. >> reporter: a woman's, she thought? she went outside to tell her mom. >> and i said, "did you hear that scream?" and she said, "yeah, but i think it's just kids playing in the -- playing in the pool." >> reporter: kids? at 6:00 something in the morning? lindsay walked over to the six-foot brick wall between their yard and the halls'. she stepped on the planter, she said, and looked over the wall. >> at that point i saw a man with his hands -- one hand on top of a woman's head and then one hand on her back. and she was face down in the water. >> like something was going on? >> yeah. that's what i assumed. >> reporter: that is, she thought she was looking at a sex act in progress. >> i don't know