Jurors have ruled a former Marine in Southern California who went by the nickname “Psycho,” should get the death penalty for the execution-style murders of a fellow service member and his wife.

A Riverside County Superior Court jury deliberated for about half a day before handing down the decision Thursday against Fallbrook resident Kesaun Sykes, 27.

It was the same jury to find him guilty of two counts of first-degree murder in the deaths of newlyweds Marine Sgt. Jan Pietrzak, 24, and his wife, Quiana Jenkins-Pietrzak, 26, who were found brutally killed in their home near Murrieta in October 2008.

Former Lance Cpl. Sykes was also found guilty of special circumstances of murder during the commission of a robbery, burglary and rape by an instrument.

His sentence is scheduled to be certified by a judge on Nov. 7.

Three other former Marines – Kevin Cox, Emrys John and Tyrone Miller – were convicted last June on the same counts in the Pietrzak slayings.

Juries ruled John and Miller should also be put to death and that Cox should get life in prison without the chance of parole.

Sgt. Pietrzak, a helicopter airframe mechanic at MCAS Miramar, once worked with Cox, John and Miller while they were stationed at Camp Pendleton.

Jurors have convicted three former Marines of torturing and killing a fellow Marine and his wife for money in a 2008 execution-style slaying in Southern California. NBC’s Tony Shin reports.

Before the killings, the four convicted Marines went to the victims’ home to rob them, forcing their way inside, the DA says.

Pietrzak was later found bloodied and beaten to death inside his home, while his wife’s body was discovered naked. Investigators say she had been sexually assaulted before her murder.

Both victims were bound and shot in the head.

Jewelry, including the couple’s wedding rings, as well as Pietrzak's dress uniform were found at the suspects' homes, authorities said.

Sgt. Pietrzak, who was born in Poland and raised in Brooklyn, N.Y., joined the Marines in 2003 and served in Iraq from July 2005 to February 2006. Relatives of the victims said Quiana was from San Bernardino and was a 2005 graduate of San Diego State University.

The couple met in San Diego through a mutual friend who also attended SDSU. Quiana was studying to become a doctor.