That question is at the heart of a lawsuit from Castle Rock, Colo., which has now made it all the way to the U.S. Supreme Court. Oral arguments in the case will be heard on March 21.
In 1999, three little girls - aged 10, 8, and 7 - were shot to death by their father. Now, their mother is trying to sue Castle Rock and its police force for not protecting her daughters.
U.S. cities are immune from most lawsuits, and the Supreme Court is being asked to decide whether the mother, Jessica Gonzales, can sue in this case. It's a decision, reports Correspondent Mike Wallace, that could affect police departments across the country.
Sisters Rebecca, Kathryn and Leslie Gonzales were known to their friends as "three peas in a pod."
The sisters were a fun-loving trio, even though their parents were getting divorced. Their mother, Jessica, said her estranged husband, Simon, had been frightening the family by acting erratically. He even put a noose around his neck and attempted to hang himself in front of the girls.
"I went out in the garage and found him standing on this stool, and his neck in the noose, and the children are standing at the door watching this," says Gonzales. "And I was holding the rope away from his neck. And I made the girls call the police, because I couldn't do it myself."
There were repeated calls to the police, because Simon kept scaring the family, even after the couple separated. "He would stalk us. He would break into the house," says Gonzales. "He didn't have a key, when he wasn't living there. And it frightened us because we didn't expect him to be there."
Gonzales got a restraining order to keep Simon away from her and the girls. The order stipulated that he could be with his daughters only on alternate weekends, and one prearranged dinner during the week.
But just one month after the restraining order was issued, on a night when he wasn't supposed to see the girls, Simon loaded his daughters into his pickup truck and drove off.
How did Gonzales find out that her daughters were missing?
"They'd been gone over an hour. They had asked me around 4:30 if they could go out and play. And they checked in just about every hour. And so I knew when they didn't check in with me by 5:30 something was wrong," says Gonzales, who decided that Simon must have abducted the girls.
"I had to assume it was him, but I didn't. I was afraid. I couldn't believe that he would do that. And so I told the police I believed that it was him, and they were gone."
She called the police just before 6 p.m. When officers came to her house, she says she immediately showed them the restraining order. Colorado law requires police to arrest anyone who violates a restraining order, but Gonzales says the officers did not seem very concerned.
"Their first reaction was, 'Well, he's their father. It's OK for them to be with him,'" says Gonzales. "And I said, 'No, it's not OK. There was no arranged visit for him to have them.'"
Castle Rock Police Chief Tony Lane told 60 Minutes that domestic disputes are often tough to sort out. "What safer place can children be than with one of the parents, the mother or the father," says Lane. "And we had no indication from past records that he was ever violent with these children, or even his wife, physically."
Lane said his men drove around looking for Simon. And officers told Gonzales to call them back if the girls weren't home by 10 p.m. Gonzales said Simon wasn't answering his cell phone, but he was calling his girlfriend, and the girlfriend kept calling Gonzales with disturbing news.
"She talked about him wanting to drive off a cliff, and she asked if he had a gun," says Gonzales. "And about whether or not he would hurt the children."
Three hours after he took the girls, Simon finally answered Gonzales' call and told her they were at an amusement park called Elitch Gardens, and that he'd eventually bring them home.
Gonzales then called the police and told them about her conversation: "I told them that I finally caught up with him. And where he was. And could they locate him, and bring the children home. And, as I recall, they told me that was out of their jurisdiction."
Police told Gonzales that it was out of their jurisdiction because it was in Denver instead of Castle Rock. So then, Gonzales says she asked them "if they could call Denver police, because there's one way in and one way out of the amusement park."
Gonzales says the Castle Rock police refused and that instead of sensing danger, police were treating this as merely a domestic spat.
"I practically read the restraining order to them," says Gonzales. "And I said, 'Well, what if he doesn't bring them home?' They said, 'Well, you call us back in a couple of hours.'"
Gonzales says she read them the part of the restraining order that instructs police, "to use every reasonable effort to protect the…children to prevent…violence." She also told 60 Minutes that she begged and pleaded with the police to get her girls.
But Lane disputes that. "She did not beg us to go to Elitch Gardens. In fact, she said she had told Simon to bring the kids home and he agreed to do that," says Lane. "So we were all under the impression that Simon was bringing the children home."
But Simon didn't do that. When the girls still had not returned after 10 p.m., Gonzales says she called police for the third time, and they told her to wait until midnight before calling again. At midnight, Gonzales drove to Simon's apartment.
He wasn't there, so Gonzales made her fourth call to police, and then, fighting panic, she says that, feeling frightened and frustrated, she drove to the police station. There, she told another officer about the restraining order and that her daughters had been gone for seven hours. Then, she went home.
According to police, at 3:20 a.m., Simon Gonzales drove to what was then the site of the Castle Rock police station. Police say Simon got out of his truck and started shooting at the building with a semi-automatic gun that he'd bought that evening after he'd picked up the girls.
Police returned fire, killing Simon. When they looked into the cab of his truck, they found the bodies of Rebecca, Kathryn, and Leslie. An autopsy concluded that Simon had shot each of them in the head at close range after leaving the amusement park, which meant that he'd driven around with their bodies beside him for several hours.
Who dropped the ball on this case? "Nobody dropped the ball," says Lane. "You give me a crystal ball, and you tell me that this was gonna happen ahead of time, and we would have certainly taken action on it."
Lane adds that "we certainly had no indication that Simon was gonna kill these kids."
"I would think working with a restraining order, his girlfriend thinks he's a little nuts, he's tried to commit suicide on more than one occasion," says Wallace. "I would think that it would occur to the cops, 'Hey, this guy's crazy.'"
Says Lane: "These officers acted on the information that was available to them, at the time."
Chief Lane says the officers that night apparently did not know that Simon had recently been ticketed for road rage, and for trespassing in a private section of their own police department, after police served him with the restraining order.
"We have upgraded our computer systems, our information systems, so we have this information more available," says Lane. "And we have a much better system in place now that we did six years ago, obviously."
But Gonzales' attorney, Brian Reichel, who will argue her case before the Supreme Court, says police didn't need to know about Simon's bizarre behavior. They just needed to follow the law. Colorado is one of 30 states that passed a law instructing the police to arrest people who violate restraining orders.
"If there's a restraining order in place, a court order in place, telling them what to do, just do it," says Reichel. "They knew exactly where he was. We have their own logs that say that Jessica called and advised the police department that Simon had the children at Elitch Gardens amusement park -- at 8:30 that night, when they were still alive."
But the cops had said that the amusement park was out of their jurisdiction. "Well, I'm assuming that Castle Rock police department have the phone number for the Denver police department," says Reichel. "A simple telephone call to the security officials at Elitch Gardens, to the Denver police department, this tragedy could have been avoided."
In hindsight, should Castle Rock police have asked the Denver police to go to the amusement park?
"That's a judgment call," says Lane. "Could we have called Denver police department? Sure. What would we have to tell them? Go to Elitch park and check on the welfare of Simon Gonzales? Sure."
And now the U.S. Supreme Court will decide whether Gonzales can sue Castle Rock for not doing enough to enforce the restraining order, not doing enough to protect her children.
Cities have immunity against most lawsuits. A federal district court ruled Gonzales couldn't sue, but then an appeals court ruled she could sue. So the Supreme Court will have the last word.
"If the Supreme Court is to decide that Jessica has no remedy, where's the accountability for the police," says Reichel. "Where, if the courts tell them to do something, and they refuse to do it, or don't do it properly, and the legislature tells them that they're supposed to act in a certain way and they don't do it, where's the accountability? Where's the accountability?"
What impact would this have on Chief Lane's police force, or police across the country, if Gonzales were to win this lawsuit?
"That would have a severe impact on not only our department, but law enforcement in general," says Lane. "It would open up the door for all kinds of liability issues."
Castle Rock will tell the Supreme Court that if this type of lawsuit is allowed, it could bankrupt some cities, because law enforcement inevitably is less than perfect.
But Gonzales says she's suing for $30 million to force police departments across the country to improve officers' training on how to enforce restraining orders.
"I don't lose three children and not do something about it. And this is the only way I know to make that right," says Gonzales. "All I can do is give it my best shot to make a change, to make the world a little safer. And if that doesn't work, then at least I know I tried. I didn't just roll over and accept it."
The Supreme Court will hear oral arguments March 21. Chief Lane sent 60 Minutes a letter after our interview. And on one key point, he agrees with Gonzales: "The tragedy of the Gonzales shootings points out the much larger problem in this country … with restraining orders. They do not protect society from the Simon Gonzales of the world."