By Dan Whitcomb

LOS ANGELES (Reuters) - The judge who gave a six-month jail term to the former Stanford University swimmer convicted of sexually assaulting an unconscious young woman has received a string of death threats after the sentence was widely condemned as too lenient, court officials said on Wednesday.

Santa Clara County Superior Court Judge Aaron Persky has come under withering nationwide criticism and faces a recall effort for the sentence he imposed last week on 20-year-old Brock Allen Turner for the January 2015 attack. Prosecutors had asked that Turner be put behind bars for six years.

"Because of all the Brock Turner stuff, people are acting poorly," Gary Goodman, supervising attorney for the Santa Clara County Public Defender's office. "They don't like the sentence."

Goodman said the threats have prompted the county sheriff's office to increase its security presence at the courthouse.

The uproar over the sentence, fueled in part by the victim's harrowing letter in which she detailed the assault in graphic terms, is part of growing outrage over sexual assault on U.S. college campuses.

The furor has also led to threats of another kind as a group of self-styled witches set up a Facebook page named "The Hexing of Brock Turner."

Because Persky ran unopposed for re-election, he did not appear on the ballot for Tuesday's primary election, but could still face a write-in candidate in November, county officials said.

A Stanford University law professor, Michele Dauber, has begun a formal effort to recall Persky in an election next year and said she expected her campaign to gather the needed signatures.

"What we need to do is replace Judge Persky with a judge who understands sexual violence against young women and wants to keep them safe on college campuses," Dauber said.

The law professor said she was "appalled," however, that Persky was receiving death threats, saying she too had received them for speaking out on behalf of the victim.

The outcry over Turner's sentence has also prompted several online petitions seeking his removal.

And the furor prompted a North Carolina pastor to write a widely circulated "open letter" to Turner's father, Dan Turner, in which he criticizes the father for seeking leniency from the judge in a much-derided missive that discussed his son's favorite foods and other memories.

"To be honest, I don’t give a damn and if his victim was your daughter I’m quite sure you wouldn’t either," John Pavlovitz wrote.

(Editing by Matthew Lewis)