An undocumented immigrant, who had been deported back to Mexico five times, stands accused of fatally shooting a young woman who has walking with her father at a San Francisco pier.

According to CNN, Kate Steinle, a 31-year-old medical device salesperson, fell to the ground after what was described as a popping sound.

Police say the killing was random.

Liz Sullivan, the mother of the victim, explained to a CNN affiliate that her daughter kept calling out to her father for help. "She fought for her life," the woman’s mother said. "They said how strong she was but they just couldn't save her."

Steinle died at San Francisco General Hospital.

Special attention is being focused on the circumstances surrounding the alleged shooter, a 45-year-old repeat felon named Juan Francisco Lopez-Sanchez. The undocumented suspect was set to be deported back to Mexico, but due to the fact that authorities in San Francisco wanted him on a drug-related warrant, U.S. Immigration and Customs Enforcement (ICE) turned him over to San Francisco deputies.

ICE claimed they had requested an immigration detainer, asking that the agency be notified before Lopez-Sanchez was released. Since San Francisco is a city that does not honor those kind of requests, the sheriff's department had no choice but to let him go.

On Friday, Republican presidential candidate Donald Trump, who has recently made waves by saying that Mexico is sending its criminals to the U.S., saw the random killing of Kate Steinle as further reason why he should be president.

"This senseless and totally preventable act of violence committed by an illegal immigrant is yet another example of why we must secure our border immediately," Trump said as reported by CNN. "This is an absolutely disgraceful situation and I am the only one that can fix it. Nobody else has the guts to even talk about it. That won't happen if I become president."