Sean Janssen, The Union Democrat

The Calaveras County Sheriff's Office on Friday released the results of its investigation into a murder-suicide about two months ago outside Murphys, concluding Philip Marshall acted alone in killing his two teenaged children, a pet Shih Tzu and himself after a history of mental illness and a messy split with the children's mother.

The six-page report details the initial investigation that took place after the bodies of the three family members were discovered Feb. 2 at the Marshalls' Forest Meadows home. It also discusses the follow-up investigation looking into theories of a triple homicide floated by skeptics.

Among the report's key findings:

• The Sheriff's Office investigation concluded Marshall, 54, shot his son Alex, 17, and daughter Macaila, 14, as they slept on the living room couch. He then turned the Glock Model 19 9mm semiautomatic handgun he purchased in October 2011 in Turlock on himself.

• On Jan. 27 - less than a week before the murder-suicide - Marshall bought the "distinctive type" of Fiocchi brand ammunition at Big 5, confirmed by a review of surveillance video at the Sonora sporting goods store. A purchase receipt found in Marshall's car showed he paid cash for the 50-round box of ammo and detectives found the clothing he wore in the video at his home.

• Documents found on Marshall's kitchen counter indicated debts of about $67,000. A spiral binder nearby repeated the debt total and contained a handwritten note saying "Debt Kill."

• Toxicology test results showed both children had moderate levelsof alcohol in their system at the time of their deaths, with Macaila registering a .05 percent blood-alcohol content and Alex .03 percent. In addition, Macaila had also apparently taken diphenhydramine, an over-the-counter antihistamine and sleep aid, commonly sold as Benadryl.

There is no indication as to whether the siblings were drinking on their own accord or with the permission or knowledge of their father, according to Calaveras County Sheriff's Office Operations Division Sgt. Chris Hewitt.

"It's one of those no one will ever really be able to know," he said.

The report found Marshall's history of mental illness, drug use and an ugly split with his wife likely prompted to the shootings.

Drugs found

Philip Marshall's toxicology screen showed the painkillers hydrocodone and morphine in his blood as well as hydroxybupropion, a derivative of the antidepressant bupropion, commonly sold as Wellbutrin.

Investigators looked at Marshall's medical records and determined he had been diagnosed with bipolar disorder.

Marshall received a prescription refill Jan. 31, the same day neighbors last reported seeing him, the report stated. Hewitt said Friday he could not immediately recall whether the refill had been for painkillers or antidepressants prescribed to Marshall.

Records obtained during the investigation showed Marshall had been dismissed and grounded by employer United Airlines in 2006 as a result of alternating periods of depression and mania.

A search warrant served at a local clinic revealed Marshall suffered from chronic back pain, mental illness, drug dependency, anxiety and depression. He received prescriptions for narcotic painkillers and anti-depressants.

Hewitt declined to say which clinic provided the drugs.

From mid-2012 through January 2013, Marshall "frequented the medical clinic seeking additional pain medications," the report stated. Clinic physicians had him sign a pain medication contract, pledging he'd take the pills as prescribed and not seek medication from other doctors.

The records indicated he had been referred to a psychiatrist but "it is unknown whether he ever attended this appointment."

Investigators consulted a doctor and FDA research showing bupropion and hydrocodone taken in combination "can have adverse reactions in regards to mental health." Any abrupt changes in usage "could result in suicide, hostility, or psychosis," the report found.

Inside a safe left open at the crime scene, detectives found five plastic bags containing a combined 1 ounce of marijuana and a 2011 medical marijuana recommendation card, various prescription medications, and just outside the safe, a Big 5 shopping bag.

A handwritten note atop the marijuana card read "Hi Sean!"

Sean Plummer is Marshall's estranged wife and Alex and Macaila's mother.

Domestic turmoil

The sheriff's investigation found a lengthy history of run-ins between Marshall and Plummer dating back to 2008.

Plummer began divorce proceedings that year.

On Nov. 11, 2008, Plummer's sister, Erin Chamberlain, then a Murphys resident, told police Marshall threatened Plummer that she "will not see December." Eleven days later, Chamberlain said she felt fearful "for the safety of the children" as Marshall repeatedly drove past her home.

Phone messages Marshall left at Chamberlain's home on Dec. 5, 2008, included statements directed at Macaila that "if you don't call me, mom is going to have problems, we don't want this," and "Macaila, this is daddy. We are going to have lunch. We need to talk right now. If not, something is going to happen." Another message: "Sean, you are going to get what's coming to you."

Marshall allegedly slapped Chamberlain at her home that day and was arrested for domestic violence but no charges were filed.

On Dec. 7, the report stated Marshall violated an emergency protection order, which only remains in effect for five court business days.

Plummer withdrew the divorce petition in 2009 but refiled in October 2012 - about four months before the shootings.

In the months in between, Hewitt said, Marshall lived with Plummer at a downtown Murphys residence. He returned to the Forest Meadows address when the second divorce petition was filed.

Despite his mental health history and documented run-ins with the law, a background check did not prevent Marshall from purchasing the handgun more than a year before the slayings.

"That's the big question that's being addressed all over the United States right now," Hewitt said. "Right now, the only thing that's going to show up is if you're declared unfit by the courts or if you've committed a crime and been convicted."

Neither occurred in Marshall's case.

Alternative theories

Follow-up investigation by the Sheriff's Office examined whether the deaths could have been a triple murder staged to look like a murder-suicide - a theory promoted by conspiracy theorists on talk radio and Internet message boards, many associated with the "9/11 Truth" movement. Marshall wrote books and appeared on radios shows and podcasts to promote his own book claiming a government conspiracy behind the 2001 terrorist attacks on the United States.

Hewitt said Friday's report is unlikely to satisfy those most devoted to the alternative theories.

"We could have gotten him committing the crime with video and they would reject that," he said.

A bedrock of the conspiracy theory is the fact no neighbors reported hearing gunshots, indicative, they contend, that a silencer was used.

Investigators conducted a ballistics test March 16 at the Marshall home. Ammunition identical to the Fiocchi 92-grain EMB-Expansion Mono-Block purchased by Marshall Jan. 27 at Big 5 Sporting Goods in Sonora was fired into melons arranged on a donated couch.

Decibel meters placed on the Marshall property and at a neighboring home recorded an average reading of 50 decibels. Comparatively, a refrigerator compressor used as a control test gave a 45-decibel reading.

The next-door neighbor present during the test heard the noise, but indicated it likely would not have been audible while asleep, the report stated. Other neighbors contacted afterward told detectives they did not hear the shots and Sheriff's Office dispatch did not receive reports of shots fired from the area when the test occurred.

Some people have questioned whether both Alex and Macaila were asleep when they were killed.

"During the multiple tests the detectives found that it took an average of a total of two seconds to shoot each victim, demonstrating that it was possible to shoot both children prior to one of them waking up," the report stated.

Witnesses interviewed by the Sheriff's Office confirmed it was common for the children to sleep on the U-shaped sectional couch in the living room rather than their bedrooms.

Detectives found no sign of forced entry into the home. All doors were closed and some were unlocked. Computers and other high-value items were left in plain sight and there were no signs the home had been ransacked.

Subsequent testing also disproved assertions that Marshall's head wound was inconsistent with his dominant hand.

Marshall died of a single gunshot wound to the right side of his head. Interviews with his estranged wife and other relatives indicated he is right-handed, Hewitt said.

"The impression left by the Glock 9mm gun barrel muzzle established that when he shot himself he held the gun rotated in an inverted (upside down) position," the report stated. "The inverted positioning of the handgun is a natural body/arm posture of someone shooting themselves, and is consistent with him having shot himself."

"It's more of a natural movement for your body to bring the gun up the way he did with your thumb facing down. … It's not 100 percent. We find (suicides) all sorts of ways," Hewitt added.

Blood splatter patterns at the home left investigators no doubt that the point-blank shot into Philip Marshall's head could not have been accomplished by another assailant present. No "void," or blank blood-free space, in the blood patterns was found. Hewitt said such voids are created when someone else is in close proximity to blood exiting a point-blank head wound.

"If something is in the way of that mist, it would create a shadow pattern … if somebody had been there, they would have created a void or blank," he said. "That person, unless they had 30-foot-long arms, could not have done it."

"There was no evidence that Phillip (sic) Marshall or his children were moved or repositioned after the shooting, which would indicate an altered crime scene," the report also concluded.

Unanswered questions

The precise time of the Marshalls' deaths will likely never be known.

Alex's last documented communication occurred at 10:40 p.m. on Thursday, Jan. 31, via an instant message sent by cell phone to a friend. Macaila sent a message to a friend by phone at 10:10 p.m. and took a self-portrait on a phone at 10:55 p.m., according to the report.

Hewitt said the girl is eating ice cream in the photo "and does not appear in distress."

The Marshall children didn't attend school Friday.

The bodies of all three family members were discovered at 3:10 p.m. Saturday after friends of Alex and Macaila went to check on them, saw Philip motionless on the floor through a window and called the Sheriff's Office.

At the Marshall home, investigators found 43 unfired cartridges in the box, one unfired cartridge appeared on the laundry room floor and four more were used to kill the Marshalls and the dog.

One cartridge remains unaccounted for, "another one of those that we don't know," Hewitt said. "One of the theories we had is maybe (Marshall) test-fired the gun."

A fingerprint analysis of the Glock identified Marshall's fingerprints on the interior plastic carton of the ammo box and the gun magazine. Prints on the gun lacked "sufficient quality and quantity of friction ridge detail" for irrefutable identification purposes but showed "similarities in ridge flow and ridge characteristics in agreement with his left thumb and left index finger," the report said.

The handwritten notes in the binder and on the marijuana card were not analyzed by handwriting evaluators, Hewitt said, but "everything we found pointed to (Philip Marshall) having written them."

A desktop and laptop computer belonging to Marshall were sent to a Sacramento lab for forensic analysis. Results are still pending.