CHICAGO (CBS) -- Chicago suffered through an especially bloody holiday weekend, with 69 people shot over the Memorial Day weekend, including six fatalities.
Police said the vast majority of the victims were on a watchlist of sorts – what the department calls its "strategic subject list."
CBS 2's Mai Martinez sat down with the Chicago Police Department's top brass to talk about how the list works.
The strategic subject list uses an algorithm to try to predict who is most likely to be involved in a shooting – either as the shooter or victim – by analyzing data such as gang affiliations, criminal records, past shootings, and previous contact with police.
Police use the data to reach out to individuals on the strategic subject list to try to get them help before a shooting occurs.
The list includes about 1,500 people, who police have said are responsible for the majority of gun violence in Chicago.
Shaquon Thomas was on the strategic subject list until he was slain in May 2015.
"He was a suspect in a case report. He's arrested. He's a victim here. He was shot," said CPD Deputy Chief Jonathan Lewin.
So how does someone get on the list?
"We don't give out the specific list of variables, but it's things like subject's trendline in criminal activity," Lewin said. "One of the highlights of this model is that it does not use race, gender, ethnicity, or geography."
The algorithm also assigns each individual on the list a score. The higher the score, the more likely that person is to be involved in a crime.
"It is a very helpful tool, in terms of predicting who will be victims or perpetrators of this gun violence," said Chicago Police Supt. Eddie Johnson. "Most of these individuals that are on the list, we've done a good job of predicting who will be victims or perpetrators of gun violence. What we're finding is that a lot of them are repeat offenders, so what we need help in is our judicial partners and our legislators to help us help hold these individuals accountable."
Meantime, police have enlisted the help of community members and social service groups to reach out to those individuals with the highest scores. In some cases, police and others will visit their homes in what are called "custom notifications," to offer help.
"To give someone some options is a real positive from the police side, as well," said CPD Deputy Chief Dave McNaughton.
Christopher Mallette, executive director of the Chicago Violence Reduction Strategy, said about one in four people who receive such notifications will ask for help. However, he said it's too early to tell how many of those stay on the right path.
Johnson said police want those people to know officers are there to help them.
"That's why we're taking the time to knock on their doors. We're not coming to arrest you. We're here to provide information to help you turn yourself around," he said.
As for those who don't take police up on their offers for help, Johnson said, "those individuals need to know that if they choose to stay in that lifestyle, we'll come after them with everything that we have."
Police have made approximately 1,400 custom notifications over the past three years. Officials said another goal of the visits is to get friends and family of those on the strategic subject list to warn their loved ones of the danger they face.
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