Moments after tech mogul Bob Lee was fatally stabbed he shouted into his phone: "Help! Someone stabbed me", according to CCTV footage of the scene.
The tech executive was seen walking the streets holding onto his wound as he bled onto the sidewalk.
Police were called by 43-year-old Mr Lee after being stabbed shortly before 2.30am on April 4 in the Rincon Hill neighbourhood of San Francisco, California, US.