Chicago Tribune reporter Peter Nickeas recaps the overnight crime report which included 3 shootings across the city and a elderly woman hit by car. (Posted on: December 24, 2013)

Someone in a ski mask shot up an "impromptu memorial" Monday afternoon near the site of an earlier gang killing, police said, wounding two young men in the Humboldt Park neighborhood.

Two other shootings followed in Logan Square over the next five hours – one in the 2500 block of North Avers Avenue that wounded a 29-year-old man and one in the 2300 block of North Ridgeway Avenue that left a 22-year-old dead.

It's not clear that the three shootings are related, but police said they are investigating the possibility that the shootings that followed the first were retaliatory, based on their timing and location.

The gang that claims St. Louis Avenue and Hirsch Street, where the young man was killed earlier this year and the two men were shot about 2:40 p.m. Monday, fights with gangs north and west of there.

The first shooting, in the 300 block of North St. Louis Avenue in Humboldt Park, left 18-year-old and 21-year-old men wounded; both were taken to John H. Stroger, Jr.  Hospital of Cook County. The two were at the memorial for Ramon Colon, shot on March 6 at the intersection of St. Louis and Hirsch, when shots were fired from a Volvo SUV, hitting the younger man in the buttocks and the older man in the leg. It’s not clear how many people inside the SUV fired shots; several were wearing ski masks.

No one is in custody in connection with that shooting, police said.

A 29-year-old was wounded less than three hours later in the 2500 block of North Avers Avenue in the Logan Square neighborhood. The man shot was in a car about 5:10 p.m. when someone on the street opened fire, hitting him. He was taken to Advocate Illinois Masonic Medical Center with a leg wound.

About ninety minutes later about four blocks away, police found a 22-year-old man bleeding from gunshot wounds to his chest, abdomen and legs in an alley on the 2300 block of North Ridgeway Avenue. The Cook County medical examiner’s office identified the man as Alexander Rodriguez, of the 2200 block of Meade Avenue. He was pronounced dead at Advocate Illinois Masonic Medical Center about 8:30 p.m.

Detectives are questioning one person in connection with that shooting.

Also, about 9:30 a.m. Tuesday morning, a 46-year-old man was shot when three men forced their way into his apartment in the 2700 block of North Mango Avenue in the Belmont Central neighborhood on the Northwest Side, police said. The man was taken to Adventist Illinois Masonic Medical Center in serious condotion, police said.

Police later arrested and charged three men in connection with that shooting.

In another Tuesday shooting, a 17-year-old boy was shot in the leg about 1:10 p.m. in the 5000 block of West Lake Street in the South Austin neighborhood on the West Side, police said. The 17-year-old heard shots and felt pain, police said; no other details were available about the shooting. He was taken in good condition to Mt. Sinai Hospital. No one is in custody.

pnickeas@tribune.com | Twitter: @PeterNickeas