SAN BERNARDINO, Calif. -- Closing arguments began Tuesday in the case against Charles Merritt who is accused of killing the McStay family who disappeared in 2010.
The bodies of Joseph McStay, his wife Summer, and their two young children were found buried in shallow graves in the Mojave Desert near Victorville in 2013.
Merritt, who was business partners with Joseph McStay, was arrested in connection to the murders in November 2014.
"The killing of Summer and those kids, Joe was senseless and violent. Violent with the use of a heavy object similar to the sledgehammer found in the grave with Summer," said the San Bernardino Deputy District Attorney. "It was blow, after blow, after blow to a child's skull a 3-year-old and a 4-year-old that is an intentional killing."
During the proceedings prosecutors say Merritt had motive, emails showed that he owed Joseph McStay over 40 thousand dollars.
Prosecutors presented evidence showing that Merritt stole thousands of dollars from Joseph’s business by forging checks and hacking into his electronic bank account.
Forensic cell phone evidence was presented in court to show a timeline leading up to the killing and where the defendant was the night the family disappeared.
"What’s also important, is at that point the defendant goes off the grid,” said the prosecutor.
Merritt, who has opted to defend himself, faces the death penalty if convicted.
Merritt's defense will present it's closing arguments Wednesday and then the case will be handed to the jury.
This is a developing story. Check back for updates.