UPDATED at 4:30 p.m. with experts discussing depression.
DE SOTO • A woman apparently fatally shot her three daughters with a shotgun, then shot and killed herself outside the home of her ex-boyfriend, authorities say.
Authorities believe Lisa R. Cochran, 32, shot each of her daughters — Alyssa Cochran, 11, Autumn Cochran, 10, and Faith Ehlen, 22 months — in the head. They were found in Cochran's vehicle outside the ex-boyfriend's home, south of De Soto. She then shot and killed herself near the steps to the home.
Sheriff Oliver "Glenn" Boyer said Cochran sent an email to her family members, friends and ex-boyfriend Wednesday night that indicated she was considering murder-suicide. She "couldn't take it any more," according to the email.
The subject line of the email was "goodbye," Boyer said.
The email was sent just before 8 p.m. It wasn't yet clear when Cochran and her children died, and Boyer said there was no indication any of the email's recipients read it in time to do anything.
Near Cochran's body, authorities found a 12-gauge shotgun she had purchased at a Walmart in Arnold on Aug. 29, Boyer said.
"That information, the purchase of the shotgun and compiling everything we have so far, leads us to believe we're dealing with a murder-suicide and not a homicide," Boyer said.
The woman's estranged boyfriend, Christopher Ehlen, was questioned as a witness by police. The crime scene is at his home at Vineland and Wilson Hollow roads, where he told deputies he came home to find Cochran's vehicle parked in his driveway about 12:30 this morning.
Cochran got a restraining order against Ehlen on Aug. 13. Ehlen didn't want to get in trouble for being near her, so he backed away from the home and called for a deputy, Boyer said.
Authorities arrived and found the three girls and their mother dead.
"I've been in law enforcement for 38 years, and unfortunately I've have had to witness a couple of these incidents similar to this, and this was just as horrific as anything I've seen in my 38 years," Boyer said.
Ehlen was the father of the youngest child. Cochran was divorced from another man, the father of the older children.
The street leading to the crime scene was blocked by deputies this morning. The area is near the Washington County line.
Cochran had lived with Ehlen for a time, but recently was living elsewhere with relatives.
Boyer said they interviewed Ehlen extensively and he was cooperative. Authorities are still investigating, he said.
Todd Scott, assistant superintendent of the Fox C-6 School District, said Alyssa was a sixth-grader at Antonia Middle School and that Autumn was a fifth-grader at Antonia Elementary School.
Scott said the district's crisis team visited the schools today to offer grief counseling to students and will continue to offer counseling as needed.
"We're deeply saddened by this incident and we want to try to help our students deal with the grief," Scott said.
If the deaths are ruled murder-suicide, this would be the third time this year a mother in the St. Louis area shot and killed her kids before shooting herself.
On July 30, authorities say Glendale mother Catherine Murch, 42, shot her son, Mitchell, 10, and daughter, Mary Claire, 8, with a pistol she bought a few days earlier, then killed herself, all while her husband was elsewhere in the home.
On March 17 Ballwin mother Christine Adewunmi, 37, and her three children — Lauren, 8, Samantha, 6, and Kate, 3 — were found dead at a campground near Bourbon, Mo. Authorities say she drove there, then shot the children and herself with a handgun.
Experts who treat mothers suffering from severe mental illness say its unusual to have three similar incidents in the local area within a short time.
"You hear about one or two cases in certain part of the country, but this is happening all within the St. Louis area," Dr. John Rabun, a clinical instructor of psychiatry at Washington University, said. "It's uncommon for it to be so close in time in a close locale... It's an anomaly. It raises eyebrows."
Some depressed women become convinced that life is so terrible that their children are better off dead, according to Diane Sanford, an adjunct professor at St. Louis University, who has written two books on postpartum depression. They believe they are protecting their children from suffering by ending their lives.
"Mothers don't kill their children unless they are very ill," she said.
Kim Bell, Leah Thorsen, Aisha Sultan and Joel Currier of the Post-Dispatch contributed to this report.