A man charged in the shooting deaths of three people, including two killed in Mission Valley on Christmas Eve, is not competent to stand trial, according to a psychiatrist's report made public Monday.
A prosecutor said his office may ask for a trial to determine if Carlo Mercado is capable of understanding the charges against him and assisting in his defense.
Carlo Mercado, 29, is charged with murder in the deaths of Ilona Flint and Salvatore Belvedere on Dec. 24 and the murder of Belvedere's older brother, Gianni, whose body was found in the trunk of his car in Riverside on Jan. 17.
After Mercado's arraignment, Deputy Public Defender Gary Gibson asked for a mental competency evaluation.
Monday, Judge Joseph Brannigan said the court-appointed doctor found that Mercado is not competent, but Deputy District Attorney Brian Erickson asked for time to decide if his office wants a trial on the matter or will go along with the psychiatrist's finding.
Two other doctors hired by the defense have also reported that Mercado is incompetent to stand trial, the attorneys said. Another hearing is set for next week.
If Mercado is ultimately found not competent to stand trial, he would be sent to a state mental hospital until his competency is restored.
Erickson told a judge at a preliminary hearing that Gianni Belvedere, 24, was last heard from about 11:30 p.m. last Dec. 23 when his phone conversation with a male relative abruptly ended.
Salvatore Belvedere and Flint, both 22, were shot about 90 minutes later. Erickson said a silencer was probably used in the killings because no gunshots were heard on a 911 call from Flint as she was shot.
The prosecutor said Mercado's DNA was found on a can of air freshener and tape used to hold down the trigger to quash the smell of Gianni Belvedere's decomposing body in the trunk of his car.
Mercado was arrested Jan. 18 at the San Clemente checkpoint when an agent noticed a weapons case in the back seat of his vehicle.
An assault rifle, two handguns and a homemade silencer were found in the car.
San Diego police Detective Tim Norris said in a search warrant that he believes Mercado participated in all three killings, but wasn't sure if the defendant acted alone or if others were involved.
A motive was not clear.
Mercado faces a special circumstance allegation of multiple murders. District Attorney Bonnie Dumanis has not said if Mercado would face the death penalty or life in prison without parole if he's convicted.