SAN BERNARDINO, Calif. (CBS 8/AP) — On Monday, a judge ordered Charles "Chase" Merritt, who is accused of killing the McStay family from Fallbrook, to stand trial.

Merritt will stand trial on four counts of murder. Judge Michael Smith said there was sufficient evidence for Merritt to stand trial.

The evidence includes: QuickBooks checks, DNA in the family's Isuzu Trooper, and cell-phone pings near the grave sites. There is no physical evidence actually linking Merritt to the murders but cell-phone pings do place Merritt near Victorville, the area where the graves were found.

Authorities had kept quiet for months about what drove them to charge a California man with killing a family of four and burying their bodies in shallow desert graves.

But San Bernardino prosecutors on Monday revealed the case they've been building against 58-year-old welder Charles "Chase" Merritt for the murders of his business partner, Joseph McStay, the man's wife and their two young sons.

Merritt, who was arrested last November, has pleaded not guilty to the quadruple murder, which could become a death penalty case.

The McStay family vanished in February 2010, puzzling investigators who said there were no signs of forced entry at the home, nothing was missing, and the couple's credit cards and tens of thousands of dollars in bank accounts were untouched.

More than three years later, the family's remains were found 100 miles from their Fallbrook home in San Bernardino County.

Prosecutors allege a sledgehammer was used to bludgeon Joseph McStay, 40; his wife, Summer, 43; and their sons, 4-year-old Gianni and 3-year-old Joseph Jr.

Mettias said nothing on the sledgehammer could be traced to Merritt, and questioned prosecutors' ability to link his client to the crimes.

"We have serious issues with the state of the evidence," he said. "I could see where they chose, OK, we're going to go with this guy, but nothing that is going to prove his guilt."

Prosecutors allege Merritt used the financial web site QuickBooks to print and cash checks from bank accounts from McStay's fountain business both before and after the family went missing.

New evidence revealed at Monday's preliminary hearing included:

- Merritt told San Diego investigators in February 2010 that he had never driven the family's Isuzu Trooper, which was found abandoned at the San Ysidro border crossing. Yet, a forensic analysis of the Trooper found trace amounts of Merritt's DNA on the vehicle's steering wheel and gear shifter.

- On February 6, 2010, Merritt's mobile phone made ten cell phone calls from the Victorville area. Six of the ten calls pinged on an AT&T cell phone tower closest to the location of the McStay graves near Victorville. A forensic review of the data showed Merritt's phone was located to the east of the cell tower in the same area where the bodies were buried. Merritt has a sister who lives to the west of the cell tower. She told investigators that Merritt had not been to her house since 2009.

- Merritt's cell phone also pinged in the Fallbrook area on February 9. Merritt's cell phone did not ping at any time close to the border in San Ysidro. On several occasions, Merritt's cell phone was either dead, or turned off, or out of cell phone range for hours at a time, including five hours of inactivity on Feb. 5 and six hours of inactivity on Feb. 8.

- The McStay graves were designated by investigators as grave A and B; grave A being located to the north and grave B to the south. Joseph McStay was found in grave A and the scattered remains of Joey, Jr. were found nearby. The remains of Summer McStay and her son Gianni were found in grave B, along with the alleged murder weapon, a 3-pound mini sledgehammer. Cause of death was determined be blunt force trauma to the head in three victims, but could not be determined for Joey, Jr. Joseph McStay suffered a broken rib, a broken leg and four impacts to the skull. The father's body had an extension cord wrapped around its neck and the body itself was wrapped in a futon cover, believed to have come from the family's Fallbook home. Gianni suffered at least seven blows to the head, according to court testimony.

- Paint found on the sledgehammer matched paint found on Summer McStay's bra, which was buried with her body. Also in the graves, investigators found a shop towel consistent with a roll of shop towels in the family's garage. None of the victims had shoes on and no footwear was found at the grave site.

- In February 2010, Merritt was living with his girlfriend and mother of his three children on Church Street in a Rancho Cucamonga apartment complex. He was driving a white, 1999 Chevy 3500 pickup truck. The truck's wheelbase of 73 inches matched tire tracks near grave A. Tire tracks near grave B had a width of 76 inches. No evidence points to what vehicle may have left the 76" wide tire tracks.

- Michael McStay told police he had never met Merritt prior to the time the family went missing. Michael McStay and Chase Merritt met at the house on Feb. 13, 2010, when Michael climbed through an unlocked, rear window and then let Merritt in through the front door. Michael told police Merritt was acting suspicious because he would not go upstairs, and did not touch anything in the home.

- By the time San Bernardino Sheriff detectives served a search warrant on the Fallbrook home in August 2014, the new owners of the home had replaced all the flooring and baseboards in the former McStay home and repainted the bathrooms.

- During a Feb. 17, 2010 interview with San Diego Sheriff detectives, Merritt referred several times to his business associate Joseph McStay in the past and present tense, as well as Summer McStay.

- Prosecutors allege Merritt used Joseph McStay's QuickBooks online account to print and deposit several checks before and after the McStays went missing in Feb. 2010. Some of the checks had been backdated to Feb. 4, 2010. Some of the checks were printed out but not deposited, which accounts for differing dollar amount totals in other media reports. The transactions where checks were actually deposited are below, according to prosecutors:

Feb. 2, 2010 - $2,495 check written to Charles Merritt
Feb. 5, 2010 - $4,500 check written to Charles Merritt
Feb. 5, 2010 - $1,650 check written to Metro Sheet Metal in Azusa, CA
Feb. 5, 2010 - $250 check written to Metro Sheet Metal in Azusa, CA
Feb. 5, 2010 - $2,350 check written to Charles Merritt
Feb. 8, 2010 - $6,500 check written to Charles Merritt

- On Feb. 8, 2010, someone using Merritt's cell phone called QuickBooks customer support and told them he needed to have all the transactions deleted from Joseph McStay's account.

- During an October 22, 2014 interview with San Bernardino detectives, Merritt claimed he had not been to the high desert area in Feb. 2010, and offered multiple stories to account for the QuickBooks transactions.

- Detective Ryan Smith of SBSD testified that Merritt made several ATM withdrawals from Southern California casinos between Feb. 9 and March 12, 2010, totaling a few thousand dollars.

- Merritt left no voice mails on Joseph McStay's cell phone after Feb. 4.

- The white vehicle widely reported to be the McStay family Isuzu caught on a neighbor's surveillance camera on the evening of Feb. 4 was determined by San Bernardino investigators not to be the Trooper. The vehicle was not identified during the hearing and the surveillance video was not played in court. The family's Isuzu Trooper was excluded because the vehicle in the video had a muffler on the wrong side and reflectors not present on the Trooper.

Merritt is set to be re-arraigned in San Bernardino on four counts of murder on June 24 at 8:30 a.m.