it was a hot saturday afternoon in sarasota when registered nurse trish murphy heard a disturbance coming from the stairwell just outside her apartment. >> it sounded like somebody was being chased. and then i heard somebody yell, "oh god, no." >> reporter: the unmistakable sound of gunshots followed. four of them in quick succession. trish immediately called 911. >> 911, what's the location of your emergency? >> i just heard gunshots. and somebody screaming outside and somebody running outside. >> i think my heart was probably going a gazillion miles a minute, you know? >> reporter: trish slowly peered out of her apartment door and saw a man lying in the stairwell bleeding. she knew he wasn't a resident of the apartment complex. >> i had no idea who he was. my concern was to get him over on his side because he was face down in a really big pool of blood. >> reporter: trish wasn't the only one at the scene. her upstairs neighbor, dianne mcknight, also tried to aid the victim. >> there was just blood everywhere. and i just didn't know what to do. i ran back into my apartment and got towels