The McStay family disappearance stumped investigators for years.
There were no signs of forced entry into their San Diego County home and the couple's credit cards were untouched.
But then their remains were found years later in a remote desert location more than 100 miles away. And authorities charged a former business partner of the McStay family patriarch. Charles "Chase" Merritt, 61, allegedly bludgeoned his business partner, partner's wife and two young sons with a sledgehammer before burying them, prosecutors said.
He now faces trial in the murder of Joseph McStay, McStay's wife Summer, and their 3- and 4-year-old boys.
Merritt, who could face the death penalty if convicted, has pleaded not guilty.
This timeline documents the events leading up to and following the report of the family's disappearance.
Jan. 28, 2010 – Someone using the McStay's computer searched for information about travel to Mexico and passports for children days before they disappeared.
Jan. 31, 2010 - Family celebrates youngest son Joseph Jr. 3rd birthday.
Feb. 4, 2010 - Joseph McStay stopped answering his cell phone, according to his brother. Summer McStay last spoke with her sister. Summer and Joseph text each other around 5 p.m.
Feb. 4, 2010, 7:47 p.m. - Surveillance camera at a neighbor's home shows family's Isuzu trooper leaving the cul de sac. Camera does not show who is in the vehicle.
Feb. 4, 2010, 8:28 p.m. - Fallbrook cellphone tower pings Joseph's phone. He makes a call to an employee in Rancho Cucamonga to talk about work.
Feb. 8, 2010 – Family's 1996 Isuzu Trooper towed from a parking lot near San Ysidro, Calif. Security guards later tell investigators that it may have been parked there sometime between 5:30 p.m. and 7 p.m.
Feb. 10, 2010 - San Diego County sheriffs deputies conduct a welfare check on the McStay home. No signs of foul play, deputies do not go inside.
Feb. 13, 2010 - Mike McStay (Joseph's Brother) crawls inside an open window, searching for family. Finds family dogs had not been fed and food was left on the counter in the kitchen.
Feb. 15, 2010- Family members report the family missing to San Diego County sheriff's deputies.
Feb. 19, 2010 – Homicide investigators search the family's home on Avocado Vista Lane in Fallbrook, Calif. They say there was no sign of struggle.
Feb. 22, 2010 – Deputies say the disappearance has them baffled.
Feb. 23, 2010 - Detectives notify Interpol to be on the look out for McStay family who might be traveling in Mexico.
Feb. 25, 2010 – Officials distribute fliers and ask Mexican authorities for a search of airports, bus stations and other major travel hubs.
March 5, 2010 - Video released by deputies shows images of a group of people similar to the McStay family going hand in hand into Mexico through the pedestrian gate. The video is dated around 7 p.m. Feb. 8.
March 18, 2010 – Relatives allow media to tour the McStay family home.
March 30, 2010 – FBI joins the investigation.
May 13, 2010 - Seven investigators arrive in El Rosario, Mexico after a tip from the staff of a local restaurant. The waiter accurately described a birthmark on Joey McStay's forehead.
June 19, 2010 – The McStay family mystery was featured on "America's Most Wanted."
August 3, 2010 – Family belongings are removed from the McStay family home by relatives.
April 9, 2013: Based on surveillance video captured at the border crossing, San Diego Sheriff's Department investigators announce that the McStay family left for Mexico voluntarily.
Nov. 11, 2013 - Motorcycle rider finds human remains in northern Victorville desert.
Nov. 12, 2013 - Forensic investigators including an anthropologist work through day and night uncovering two grave sites with multiple human remains.
Nov. 13, 2013 - Sheriff's investigators conclude that remains of four people have been discovered.
Nov. 15, 2013 - San Bernardino County Sheriff John McMahon identifies the bodies found as Joseph, Summer, Joseph Mateo and Gianani McStay.
Nov. 7, 2014 - San Bernardino County Sheriff's investigators announce the arrest of Charles Chase Merritt. The former business associated of Joseph McStay is charged with four counts of murder in the McStay slayings.
Nov. 11, 2014 - San Diego Sheriff Gore defends his department's investigation of the McStay family disappearance.
Nov. 7, 2014 - Family and friends of Merritt say there's no way he could have murdered anyone.
Nov. 20, 2014 - Defense attorney say Merritt suffers from poor health.
Jan. 30, 2015 - Merritt requests to represent himself saying he has only six to eight months to live and cannot afford an attorney.
Jan. 7, 2019 - Opening statements set in Merritt's murder trial in San Bernardino County after numerous delays.