San Francisco (CNN)Kate Steinle was walking on a busy pier in San Francisco with her father when there was a single popping sound in the air.
She fell to the ground, struck by a bullet, the victim of what police say appears to be a random killing.
The man accused of firing the deadly shot -- 45-year-old Juan Francisco Lopez-Sanchez -- is an undocumented immigrant, a repeat felon who has been deported five times to Mexico, according to immigration officials.
It would have been six, a federal law enforcement source told CNN, except authorities in San Francisco wanted him on a drug-related warrant.
So U.S. Immigration and Customs Enforcement, which had Lopez-Sanchez in its custody in March after his release from federal prison, turned him over to San Francisco deputies. ICE said they requested an immigration detainer, asking that the agency be notified before Lopez-Sanchez was released.