San Diego County Sheriff’s Department (SDSO) officials confirmed Monday that a once-hospitalized man suspected in the mysterious, high-profile slayings of three San Diegans has been returned to custody.
In July, Mercado was transported from San Diego Central Jail in downtown San Diego Tuesday afternoon to UC Medical Center. Caldwell said Mercado, along with his cellmate, Abel Martinez, 52, were observed by deputies to be in "medical distress".
NBC 7's source close to the investigation believes the inmates overdosed.
Martinez was returned to jail on July 30, and Mercado returned days later on August 6.
The killings began with a shooting on Christmas Eve 2013 in the parking lot of Westfield Mission Valley mall.
A judge ruled in July that Mercado would stand trial in the triple homicide case, with his trial set to begin on April 3, 2017.
In February 2016, Mercado pleaded not guilty to the slayings.
At that time, San Diego County Deputy District Attorney Brian Erickson said the District Attorney’s office would seek the death penalty if Mercado’s trial moved forward and if he is convicted.
Over the past two-and-a-half years the triple homicide case has seen many twists and turns.
Prosecutors have said it does not appear Mercado was in any way connected to the victims and that the killings are believed to have been random, or perhaps the result of some type of “road rage” incident. The killings do not appear to have been a hit, as has been speculated, prosecutors said in February.
Still, the motive for the slayings remains shrouded in mystery.
Several months ago, Mercado’s defense attorney Gary Gibson said he was disappointed with the DA’s decision to pursue the death penalty in this case given Mercado’s history of mental illness. Gibson said his client is a “deeply damaged individual with significant mental health issues.” However, Erickson argued Mercado’s mental state is directly linked to the case, which includes depression “based on his situation.”
Gibson said the case will be difficult to prove at trial because prosecutors are struggling to pin down a motive.
On Dec. 24, 2013 Flint and Sal were found critically shot inside their car parked outside a Macy’s department store at Westfield Mission Valley mall in San Diego’s Mission Valley area. Flint, who called 911 to report the shooting and their location, died at the scene. Sal was hospitalized and died a few days later.
Flint’s fiancé and Sal’s brother, Gianni, went missing around the same time of the Christmas Eve killings. On Jan. 17, 2014 police found Gianni’s badly decomposed body stuffed into the trunk of his own car parked at a shopping center in Riverside, California, more than 100 miles away from San Diego. He, too, had been shot to death.
For six months, police reported no breaks in the baffling triple homicide case.
On June 20, 2014 the San Diego Police Department confirmed officers had arrested Mercado as the suspect in the three slayings. Mercado pleaded not guilty to three counts of first-degree murder.
At a pretrial in early September 2014, DNA evidence emerged linking Mercado to Gianni’s car and the bloody Riverside crime scene, while ballistics evidence linked a gun registered in Mercado’s name to the deadly shootings of Flint, Sal and Gianni. Prosecutors also presented evidence found on Mercado's phone and computers.
Also in early September 2014, search warrants obtained by NBC 7 revealed the exhaustive investigation into the triple homicide case, but no clear motive for the killings.
In December 2014 the families of the three victims filed a wrongful death lawsuit against Westfield, LLC, accusing the Mission Valley mall of negligence in the deaths of Flint and the Belvedere brothers, claiming the mall failed to provide sufficient lighting and monitoring security cameras in the area to keep patrons safe. That lawsuit also listed Mercado as a defendant, accusing him of malice and oppression in the killings.
On Nov. 3, 2014 a San Diego judge ruled Mercado was not competent to stand trial in the triple killings, and ordered he be treated at Patton State Hospital for three years until he was found competent to assist in his own defense.
That ruling came after reports submitted by two psychiatrists and one psychologist diagnosed Mercado as schizophrenic, psychotic and suffering from catatonic depression, Mercado’s attorney said at the time.
In September 2015, Mercado was returned to San Diego Central Jail after evaluators from Patton State Hospital found him competent to stand trial. The defense then requested a competency trial for Mercado.
On Dec. 14, 2015 a judge ruled Mercado was competent to stand trial.
When Mercado’s trial date was set last week, a judge also ordered Mercado to appear in court this October for a status conference.
Meanwhile, Mercado's cellmate, Martinez, is also accused of murder.
Martinez was convicted in the shooting his ex-girlfriend, Leila Farmer, and her boyfriend, Eufracio Alberto Enriquez, in March 2014 at a home in Dehesa Valley near Alpine. Enriquez died in the shooting.
Inmate records indicate Martinez was scheduled to appear in court days after the hospitalization. NBC 7 reached out to Martinez's attorney, Thomas Bahr, at the time. Bahr said he had no comment.