Real estate mogul and Republican presidential candidate Donald Trump, who has come under fire for referring to some Mexican immigrants as "rapists" and "killers," again blasted border security in the wake of the slaying of a California woman and the news that the suspect was deported five times.

Trump did not directly refer to the comments that have cost him valuable business sponsorships and prompted denunciations from Latino groups. Instead, he focused on border security.

Other GOP contenders, after largely sidestepping the issue, are now blasting Trump's immigration remarks, with Sen. Marco Rubio of Florida the latest to do so.

In a series of tweets Friday, Trump said the shooting death of 32-year-old Kathryn Steinle at a popular tourist spot in San Francisco was unacceptable. "Our Southern border is unsecure," he said in a tweet. "I am the only one that can fix it, nobody else has the guts to even talk about it." Francisco Sanchez, 45, was arrested on suspicion of murder. Sanchez has seven felony convictions.

Our Southern border is totally out of control. This is an absolutely disgraceful. situation.https://t.co/ujz3jENIYo We need border security! — Donald J. Trump (@realDonaldTrump) July 3, 2015

Our Southern border is unsecure. I am the only one that can fix it, nobody else has the guts to even talk about it. https://t.co/ujz3jENIYo — Donald J. Trump (@realDonaldTrump) July 3, 2015

My heartfelt condolences to the family of Kathryn Steinle. Very, very sad! — Donald J. Trump (@realDonaldTrump) July 3, 2015

Where are the other candidates now that this tragic murder has taken place b/c of our unsafe border https://t.co/amaV7tqgAR We need a wall! — Donald J. Trump (@realDonaldTrump) July 3, 2015

Trump has stood by his "rapists" and "killers" comments, but made no direct mention of Mexican immigrants in Friday's tweets.

Fellow Republican candidates this week said that Trump has gone too far.

"His views are not reflective of the immigrant experience. He’s just wrong," former Florida Gov. Jeb Bush told the The Daily Caller.

Former Texas Gov. Rick Perry, in an interview on Fox News, called Trump's comments a "huge error" that "painted with a very broad brush."

"I don't think he's reflecting the Republican Party," Perry said.

Rubio released a statement, posted Friday by CNN's Jake Tapper, condemning Trump's comments, calling them " offensive and inaccurate, but also divisive."

"Our broken immigration system is something that needs to be solved, and comments like this move us further from -- not closer to -- a solution," according to the statement.

Still, Trump does have support from at least one other GOP candidate, Sen. Ted Cruz of Texas, who defended Trump to Chuck Todd in an interview on NBC’s “Meet the Press.”

“I salute Donald Trump for focusing on the need to address illegal immigration,” Cruz said. "The Washington cartel doesn't want to address that."

Several companies -- including Univision, NBC and Macy’s -- have severed ties with Trump because of those comments. Trump filed a $500-million lawsuit against Univision alleging breach of contract.

However, his stance on immigrants living in the country illegally does not seem to be hurting him in recent national polls, which have him in second place among Republicans.

Follow Ryan Parker on Twitter, Facebook and Instagram