17 January 2017 :

Nearly two-thirds of death row prisoners in five Florida counties whose cases were studied by Harvard University's Fair Punishment Project suffer from serious mental impairments.
According to a report released by the project on January 12, 2017, the Florida Supreme Court's December 2016 ruling in Mosley v. State requires reconsideration of the sentences imposed on approximately 150 people on Florida's death row who were sentenced to death after the U.S. Supreme Court decided RIng v. Arizona in 2002.
Based on Ring, Florida's death sentencing procedures were later ruled unconstitutional.
Nearly one-third of the death sentences in question were imposed in just five Florida counties: Duval, Miami-Dade, Hillsborough, Orange, and Pinellas.
The Fair Punishment Project report examines the 48 death sentences from those counties that involved non-unanimous jury recommendations of sentence or waivers of jury sentencing proceedings.  
It finds that in 63% of those cases, the defendants "exhibit signs of serious mental illness or intellectual impairment, endured devastatingly severe childhood trauma, or were not old enough to legally purchase alcohol at the time the offense occurred." Those impairments, the report argues, makes the death penalty disproportionate for those defendants.
Defendants in more than a third of the cases (35%) had low IQ scores or traumatic brain injury that left them with deficits similar to people with intellectual disability, whose diminished culpability makes them constitutionally ineligible for the death penalty.
Approximately 1/5th of the 48 defendants presented symptoms or diagnoses of severe mental illness; approximately 23% had experienced severe childhood or emotional trauma; and 6 were under the age of 21 at the time of the offense.
More than a quarter had overlapping impairments from multiple categories.
The report concludes, "These findings have raised a legitimate question as to whether Florida’s capital punishment scheme–even one with a unanimous jury requirement– is capable of limiting application of the death penalty to the most culpable offenders."