The latest carnage came Sunday, when a 28-year-old mother was just steps from the entrance to a suburban Los Angeles police station.
Jacob Munn, toting a shotgun and a heavy grudge, allegedly pumped two rounds into the head of his ex-girlfriend and the mother of his 17-month-old son, according to authorities. Brenda Renteria dropped dead on the pavement, in front of her screaming relatives and horrified civilian employees on the other side of the station's entrance.
Renteria became the most recent statistic in the violent specter of parents who are allegedly gunned down by an ex-spouse in what was supposed to be a public meeting to exchange custody of their children.
There are no statistics on such fatalities, say experts on the subject. But it is a growing problem with no immediate cure, they say.
"It's off the charts," Joe Nullet, executive director of the Supervised Visitation Network, told InsideEdition.com. "In the old days, they used to talk about drug deals gone bad, but they pale in comparison to custody exchanges gone bad."
There are procedures designed to prevent exactly what happened to Renteria, he said.
"The worst thing they can do is go to a police station. People can get ambushed, confronted and, in this case, actually get shot. The police don't even know they're there," Nullet said.
His group provides training to state and local agencies that offer supervised custody exchanges.
Paramount in contentious custody battles is making sure neither parent sees the other when custody of their children is being swapped.
"If you've got a father who is at risk for gun violence, this father would have to show up first" to a prearranged meeting, he said. The dad would be kept inside a building while the mother arrived later and dropped off her child to the person supervising the exchange "and be given 15 minutes to be on her way" before the child is handed over to their father, Nullet said.
That eliminates the possibility of the woman being followed or attacked, he said.
But supervised custody exchanges are not the standard, and many judges don't know such services are available when granting joint custody in contentious divorces, Nullet said. Though his organization works with agencies in all 50 states, Nullet said it was impossible to know how many people use or have access to such protection.
"It's really unfortunate," he said. "There is a way to do it the right way. There is a way to keep people safe."
Renteria probably thought she was doing the right thing when she asked members of her family to accompany her to the Hawthorne Police building. Her mother later told officers Renteria was afraid of Munn, her ex-boyfriend and a former convict who had allegedly threatened her before.
Munn arrived at the station before Renteria, police said. He had an acquaintance take the boy inside, while he stayed in the car, according to authorities. Moments later, Renteria came walking up, and just as she reached the entrance, Munn approached and fired two rounds into her head, Hawthorne Police Lt. Jim Royer told InsideEdition.com.
"She was trying to make it in the door," he said. Officers came running when they heard the booming shots. Munn was already in his car and driving away, Royer said. They fired at his vehicle, but missed, he said. After a three-hour search, officers found him trying to hide in a residential neighborhood, he said.
Munn is charged with murder, being a felon in possession of a firearm and a special circumstance charge of lying in wait, which makes him eligible for the death penalty if convicted. Officials have not said whether they plan to pursue that punishment. He is being held without bail. His arraignment is scheduled for April 24. He has not entered a plea.
"Police facilities are seen as safe havens," Royer said. "It's a common practice" for custody exchanges, he said. "It's seen as a protected place."
But as Nullet pointed out, police don't supervise the handoffs, nor do they even know they're going on. Some are held in the lobby, others in the parking lot, but officers are not involved.
"People get into arguments, it can be quite contentious," he said. But, "I've been here 32 years and no one has ever shot a person in the lobby of the police department before," he said.
Surveillance cameras captured the entire incident, he said.
Allowing police property to be used for custody exchanges doesn't particularly trouble Royer. "I would hate to think that ... we're just going to turn these people loose in the lobby of a Marriott Hotel, where no one is equipped to deal with something like this," he said.
Any solution, he said, is beyond the scope of law enforcement.
"What's going on with these people that this is the only thing they can think of to do? These are civil matters. We deal with criminal matters. These people need to be referred somewhere and they need to get help," he said.
Last month, a Pennsylvania man walked into a Wawa convenience store for what was supposed to be a child custody exchange with his ex-wife. Instead, he shot her several times in the head and stomach at point-blank range, police said. She died in the market. He was later arrested after police said they found him passed out in his car from a drug overdose. He is currently in jail on first-degree murder charges.
It's not only men, authorities say. A similar incident allegedly occurred in January, though this case involved a woman accused of shooting to death her ex-husband in the parking lot of an Ohio McDonald's. The man thought he was picking up his 9-year-old daughter, police said. The woman brought a gun instead and shot him several times, leaving him in the lot, authorities said.
She fled, but later turned herself into authorities. She has pleaded not guilty to first-degree murder.
Fighting parents, sometimes under a judge's order, often pick public places for custody exchanges thinking they will find safety in numbers. Parking lots, police stations and shopping centers are increasingly used for these meetings, but they really aren't safe havens at all, say custody experts.
"It's a really bad practice," said Nullet. If a parent "is concerned about their safety, they shouldn't agree to meet at a public place, or a police station. They should use services like ours."
Those services include lengthy interviews with both parents before an exchange takes place. Risk assessments are completed and a contract is established between both parties stipulating how, when and where the exchanges will take place, and who will arrive first.
Kindred Place, a Tennessee-based organization that offers family anger management courses, victim services and parenting support, used to provide supervised custody exchanges at their facility. They stopped doing so last year.
Safety concerns were a factor, Patricia Maynard, who oversaw those services, told InsideEdition.com.
"We had limited security," she said. "We had people showing up in our parking lot (to exchange custody) who weren't using our services," she said. There was also a drop in the number of requests for supervised handoffs, she said.
Maynard said the decrease may have reflected parents who didn't follow through with a court-ordered safe exchange program and felt they could handle it themselves.
People in conflict can rarely do that, she said. In the Memphis area, where her organization is located, there have been two shootings during custody exchanges in the past two years — one at a gas station and one at a Kmart.
In April 2016, an off-duty police officer shot and killed a man in front of a 4-year-old child at a Shell station, authorities said. The officer was dating the child's mother and was present when the father arrived to drop off the girl, police said. The two men fought, leading to the shooting, authorities said. No charges were filed in the case, authorities said, because both men were armed and the father did not obey an order to drop his gun, police said.
Six months later, in a Kmart parking lot, a mother and her new boyfriend dropping off a 1-year-old boy got into an argument with the woman's ex-partner, police said. The father shot and killed the boyfriend, then fled with the baby, according to authorities. The child was later dropped off at a police station and the father was charged with murder.
"There is added tension" to an already tense situation when "new partners are introduced" into bitter custody disputes, Maynard said. "People in conflict don't think or act rationally," she said.
But Maynard said Kindred Place never saw a single incident of violence during its supervised custody exchanges. That's because the parents involved followed the agency's rules, she said, agreeing to do what was best for their child.
Too often, that is not the norm, she said.
"A child has two parents and they have to find a way to meet in the middle," she said. "A child is not a piece of property," and being in the middle of feuding parents "does great emotional damage to the child," she explained.
"The system is broken. Women have to do all they can to protect themselves and live their lives. ... When they have a child, it becomes a pawn."