UPDATE 11:44 P.M. JULY 12: 13 Action News crime and safety expert retired Las Vegas police Lt. Randy Sutton said police will do a detailed investigation.
"What went on through his head to drive him to such a violent, abhorrent act," Sutton said.
They'll talk to family and friends as well as check out emails and cell phone records to figure out what led to this grisly end. "The suspect is dead. The victims are dead. This investigation is not going to be for a prosecution. It's going to be to understand how and why," Sutton said.
UPDATE 7 P.M. JULY 12: A family friend says Karen Jackson was planning on leaving her boyfriend, John Lunetta, before police said he murdered Jackson and their baby boy.
Jon Sanner says Jackson called him Saturday because she needed to vent about her relationship.
"The whole time she was just venting about her unhappiness and her current situation with the baby's father," Sanner said.
Sanner said Jackson never said anything about physical abuse, and she never showed fear of Lunetta.
But Sanner also said Jackson told him she was looking into moving out of her and Lunetta's home with their newborn son, John Jr., and Jackson's 11-year-old daughter because of Lunetta's issues with alcohol.
"Every single day hitting the bottle very hard, which in turn, he'd get drunk and start an argument with her," Sanner said.
13 Action News has learned Lunetta was a medical director for the American Red Cross.
The American Red Cross sent 13 Action News the following statement:
"We are all shocked and upset by this terrible tragedy, and our hearts go out to everyone touched by it. We can confirm that John Lunetta was employed with the American Red Cross Blood Services as a medical director in Las Vegas. The Red Cross cannot comment further on an ongoing police investigation, and we ask that any additional inquiries be addressed to the Metropolitan Police Department in Las Vegas for more information."
A memorial continues to grow outside the family home along with a "happy birthday" balloon because Wednesday would have been baby John Jr.'s first birthday.
UPDATE JULY 12 9:30 A.M.: The Clark County coroner has identified the family from Monday's tragic murder-suicide.
Police believe 34-year-old Karen Michelle Jackson (mother) and 11-month-old John Dylan Lunetta (child) were murdered by John Henry Lunetta (father) before he took his own life.
UPDATE JULY 11: Neighbors and friends came together to mourn the loss of a 1-year-old boy and his mother after police say the father shot and killed them before turning the gun on himself.
At this time 13 Action News is not sharing their names until they are confirmed by the coroner's office.
Tuesday night people were still trying to come to terms with what happened, choosing to lean on each other in order to deal with their grief. Many said they were hoping that what comes out of the tragedy is a stronger sense of community.
A memorial was held outside the family's home near Cactus and Rainbow. People of all ages left flowers, stuffed animals and candles on the sidewalk and the doorstep.
Jason Lindstrom's two daughters attend school with the woman's 11-year-old daughter, who was not at home at the time of the killings. He said he didn't know the family well, but couldn't help wonder if someone saw warning signs and didn't act. He said that needs to change.
"Let's not just notice. Let's do something if we become aware of someone who might be struggling, or even frustrated, or sad, or depressed," said Lindstrom. "It's amazing. I think to myself when I was these girls age, it was so easy to make friends. Now I'm in my 40s and I don't got out to make friends anymore. Shame on me."
Police believe a 40-year-old man shot the mother of his son, his almost 1-year-old son and dog at a residence near Rainbow Boulevard and Cactus Avenue on Monday night.
Officers believe the acts occurred over 24-hours ago and the bodies were just found by concerned neighbors serving a welfare check. Reports state that all bodies were found in different parts of the home.
Click the Image to Watch Facebook Live Video
The man had no prior incidents of domestic violence.
This is a developing story.
BREAKING: Man, woman, infant all dead in a home near Los Lagos/Mopan. Preliminary investigation says murder suicide. @KTNV