Aamer Madhani

USA TODAY

CHICAGO— Three children have been killed in shootings since Saturday in an ugly spasm of gun violence in the nation's third largest city that has befuddled even the most battle-hardened of Chicago Police Department officers.

The tragic killings— all three children were caught in gang-related gunfire that wasn't targeting them—come in the midst of a difficult moment for Chicago. The city is struggling to stem a surge in violence that left it with more than 760 murders last year and at least 70 homicides in the first six weeks of 2017.

As Chicago Police Superintendent Eddie Johnson announced the first-degree murder charges Wednesday against Antwan Jones, 19, for the shooting death of 11-year-old Takiya Holmes, he didn't mince words about his anguish over the unrelenting violence in this city. Authorities allege Jones, who police say is a gang member with a long rap sheet, inadvertently shot Takiya when he fired at some rivals who were selling marijuana near his apartment complex.

"For these families, my heart goes out to them, because there is nothing you can say to them that will ease that pain," Johnson said. "I can't imagine losing an 11-year-old child senselessly like this."

Takiya was sitting in a family van in front of a dry cleaners on Saturday evening, when she was struck in the back of the head by the stray bullet. She succumbed to her injuries on Tuesday.

Brendan Deenihan, the police commander of the detectives unit handling the investigation, said that gang investigators were able to help homicide detectives spot witnesses who could be seen in surveillance videos in the area at the time of the shooting. Detectives interviewed the witnesses, who identified Jones as the gunman.

Jones turned himself into police late Tuesday, and immediately asked for a lawyer. He appeared before a judge Wednesday afternoon, and was ordered held without bond.

Less than an hour before Takiya was shot, Kanari Gentry Bowers, 12, was inadvertently struck in the head by gunfire as she played basketball with friends on an elementary school playground. After four days on life support, Kanari died on Wednesday. Police have not apprehended a suspect in her shooting.

Hours after Takiya's death,another child Lavontay White, 2, was killed on Tuesday along with his 26-year-old uncle Lazarec Collins in what police said was a gang-related shooting. A pregnant woman, 20, was wounded when they were ambushed as they drove in an alley on the city’s West Side.

Boy, 2, killed in Chicago gang hit

In the fatal shooting of Lavontay, police believe the uncle Lazarec Collins, 26, a known gang member, was the intended targeted. Like the suspected gunman in Takiya's shooting, Collins had an extensive record, including convictions for armed robbery and burglary.

Anthony Guglielmi, a police department spokesman, said both Jones and Collins were spotted by the department's Strategic Subject Algorithm tool, a predictive list that the department generates to determine people who are at high risk of becoming victims or of perpetrators of a crime.

No one has been apprehended in that shooting, part of which was livestreamed on Facebook Live. Police, however, said they had promising leads in the double homicide.

Chicago has been in the spotlight over the roiling violence plaguing the city. President Trump has repeatedly suggested that he may order a federal intervention to try to stem the violence. Earlier this month, the Bureau of Alcohol, Tobacco and Firearms confirmed that it was considering the addition of more agents to its Chicago field office.

Mayor Rahm Emanuel and Johnson say the spike in violence—the city tallied more murders than New York and Los Angeles combined last year— is caused by a combination of increased gang activity and weak gun laws that they say don't do enough to dissuade convicted felons from carrying and using weapons.

Emanuel and Johnson have called on state lawmakers to pass legislation, introduced by state Sen. Kwame Raoul, that aims to lengthen sentences for felons previously convicted of unlawful use of weapons charges. The bill would not impose strict minimum sentences, but would require judges to explain their rationale in writing if they grant lighter sentences to previously convicted gun felons. About 40% of homicide suspects arrested in Chicago in 2015 had previously been convicted of a weapons offense, according to police department data.

Johnson said it was "tragic" that the state lawmakers haven't taken action.

"They (repeat offenders) think the judicial system in Cook County is a joke," Johnson said. "They just don't care. Until we create that...accountability to not pick up a gun, we're going to continue to see this cycle of violence."

Follow USA TODAY Chicago correspondent Aamer Madhani on Twitter: @AamerISmad