Do letters from the public — often or ever — influence sentencing judges?

This local story from Florida, headlined "Fans, foes of Mary McCarty flood sentencing judge with suggestions for her fate," prompts the question in the title of this post.  The local story includes quotes from letters to a federal sentencing judge concerning how to sentence a local corrupt politician, and here is the basic backstory:

With the fallen county commissioner set to be sentenced Thursday, U.S. District Judge Donald Middlebrooks is receiving a welter of missives from the public — some urging the maximum five-year sentence spelled out in her plea deal, some advocating no more than community service.

McCarty, 54, a Delray Beach commissioner and then an 18-year county commissioner, pleaded guilty in March to misdeeds that included votes on bond deals that benefited herself and her underwriter husband, Kevin. That made her the third county commissioner to fall since 2006 in a federal probe of what a state grand jury recently dubbed "Corruption County."

Dozens of people have written to Middlebrooks to weigh in on McCarty's fate, with many expressing anger at the extent of public officials' crimes. "The corruption here is everywhere," wrote one resident, Ken Eddowes. "Mary McCarty is guilty of much more and much worse than she's accused of in this case."

Added Marvin Pesses of Delray Beach: "Public officials must be held to high standards and punished severely when they dishonor their positions and the trust which we peasants have placed in our political aristocracy."

Other letters, including some from longtime friends and supporters, speak of her contrition and her years of service to help children, animals and charities. Tens of pages of such letters arrived at the court in a package submitted by her attorney in the past two weeks. "Even criminals of our society many times just get probation for the first offense," wrote Delray builder Fred Griffin, calling her crimes minor infractions. "After all it is not that Mrs. McCarty did anything to hurt the citizens of this community."

The other disgraced ex-commissioners, Tony Masilotti and Warren Newell, got five-year prison terms. Newell's subsequent cooperation against McCarty and other officials won him a judge's consent Friday to a two-year sentence reduction.

McCarty's attorney, David Bogenschutz, has urged Middlebrooks to sentence her to less time than her former colleagues, arguing that her acts were little more than ethics violations. Prosecutors are expected to counter that her crimes were far more extensive than the lone count on which she made a quick guilty plea.

In addition to those arguments, Middlebrooks is allowed to consider public sentiment as outlined in the letters.

I suppose it is accurate to say that US District Judge Donald Middlebrooks is "allowed to consider public sentiment as outlined in the letters," but it is an interesting question just how the sentiments in the letters fit into the statutory sentencing standards of 18 USC 3553(a). I suppose consideration of community sentiment could be viewed as part of the judge's requirement in 3553(a)(2)(A) to impose a sentence that will "reflect the seriousness of the offense" and "promote respect for the law."  Also, to the extent public letters discuss the offender and her crime, they can help the judge consider under 3553(a)(1) "the nature and circumstances of the offense and the history and characteristics of the defendant."

But, beyond the legal issue of just how public sentiment can be considered, there is descriptive question that titles this post.  Do these kinds of public letters often influence sentencing judges?  Do they ever?  And is there any way that researchers or policy-makers can ever know?

UPDATE:  An interested reader sent me this spot-on response to my inquiry in this post:

There is a case call Gall v. United States where the sentencing judge referred to a "flood" of letters regarding the defendant.  The Supreme Court likewise referred to those letters in discussing the trial judges sentence in that case.  To me, this is at least some "judicial notice" that these letters can and do influence sentencing outcomes.  [Also]  the administrative office has recently suggested amending rule 32 to provide that these letters must be provided to the government.  I know many local rules now provide for each side to get copies of any letters that are sent to the judge.