Two people were killed, and five others were wounded, in a shooting at a liquor store in South Shore. (Credit: CBS)

UPDATED 02/20/12 10:38 a.m.

CHICAGO (CBS) — Seven people were killed and 18 more were wounded – including a Chicago Police officer – in a violent weekend on the streets of Chicago.

One of the incidents left two people were dead, and five others injured, at a South Shore neighborhood liquor store Sunday evening.

As CBS 2’s Susanna Song reports, the shooting happened just before 7 p.m. Sunday at a liquor store in the 2500 block of East 79th Street, at the intersection with Essex Avenue.

Police say a beige vehicle pulled up to next to the liquor store, and someone inside opened fire.

Responding paramedics found two people dead on the scene, and five teenagers wounded. Jamal Harris, 19, was killed inside the store, and Greg Glinsey, who went by the nickname “Alamo,” was killed outside.

Family members of the 54-year-old say the father of four was just in the wrong place at the wrong time. They say he had left a family dinner to run to the store. Next thing his mother remembers is a commotion in another room.

“I heard noise and crying and I said, ‘What is going on down there?’ When I came downstairs, they were crying and said that he was dead,” Bertha Glinsey told CBS 2’s Roseanne Tellez.

The family matriarch turned 80 on Saturday and is thankful her son was around to mark the milestone. She says she’ll focus on the good times.

“Just think about the good things, the good memories,” she said.

Five others survived Sunday’s shooting – ranging in age from 13 to 16.

The most seriously injured was a 14-year-old boy, who was taken to Comer Children’s Hospital at the University of Chicago in critical condition after being shot in the abdomen. The other four surviving victims were shot in the leg.

Just eight minutes after the liquor store shooting, on the very same block on 79th Street, police say a 15-year-old boy was shot in the leg. The shootings do not appear to be related.

And less than an hour before the liquor store incident, a group of men chased down and killed another man in a gangway in the Back of the Yards neighborhood.

The man, identified as Clifton Harlson, 27, was shot in the neck in the 5300 block of South Hoyne Avenue, around 6:25 p.m. Sunday, police said. Sources said his assailants chased him into the gangway and shot him in close range.

Around 5:45 p.m. Sunday, a man was shot and killed near his home in the Little Village neighborhood.

Rogelio Servantes was pronounced dead after being shot in the 3000 block of West 25th Street, police said.

Earlier Sunday, one man was killed, and another was injured, in separate shootings in the 5100 block of South Hermitage Avenue in the Back of the Yards neighborhood. Tytus Harris, 22, of the 7800 block of South Wolcott Avenue, was killed in a shooting at 12:30 p.m., and about four hours later, a 37-year-old man was shot in the hand on the same block and taken to Holy Cross Hospital in good condition.

In the wee hours Sunday morning, a man was shot and killed outside a nightclub on Elston Avenue, in the largely industrial zone between the Kennedy Expressway and the Chicago River’s North Branch.

Police say someone approached two men standing near a car and started shooting outside the Krush nightclub, a weekend-only venue at 1675 N. Elston Ave., around 3 a.m. Sunday.

Asif Memon, of the 4800 block of North Winthrop Avenue, was later pronounced dead after suffering a gunshot wound to the chest, according to the Cook County Medical Examiner’s office. A 23-year-old man suffered several gunshots to the lower part of his body, and was hospitalized in critical, but stable, condition at Advocate Illinois Masonic Medical Center.

And in yet another deadly shooting, Edgar Delgado, 17, was shot at Monticello Avenue and Roscoe Street in the Avondale neighborhood around 7:50 p.m. Saturday. He was dropped off at Our Lady of Resurrection Medical Center in an older-model station wagon, and was pronounced dead at the hospital Saturday evening, police said.

In other incidents:

• A robbery suspect was shot, and a 10-year-old boy suffered a graze wound, when an attempted holdup spilled into a corner store around 5:40 p.m. Sunday in the 700 block of South Pulaski Road, also in the North Lawndale neighborhood.

The suspect, in his 30s, attempted to rob someone, but the victim fought back when the would-be robber – along with a second suspect – approached him, police said.

A struggle continued into a nearby corner store, when the gun went off during the fight. One of the suspects was hit in the leg, and was placed into police custody at the scene before being taken to Mount Sinai in critical condition.

The 10-year-old boy was a customer at the store, and he was grazed in the leg either by a bullet or a bullet fragment, police said. He fled, but his mother later took him to the hospital for treatment of the minor wound.

• A man shot a Chicago Police officer during a chase on busy Stony Island Avenue on Sunday afternoon. Calumet Area gang officers responded at 3:56 p.m. to a call of a person with a gun in the 6800 block of South Stony Island Avenue, on the cusp of the Grand Crossing and South Shore neighborhoods.

The suspect ran off, and officers pursued him to the 6700 block of South East End Avenue, where a struggle began between the suspect and one of the officers. During the struggle, the suspect pulled a gun and shot the officer, police said.

Fraternal Order of Police spokesman Pat Camden said officers then shot the suspect, a boy in his late teens, three times.

The 35-year-old officer was reported in good condition with a gunshot wound to the hand.

Police hope to have the gunman charged with attempted murder of a police officer.

• Around 3:15 a.m. Sunday, a man was shot and wounded in the thumb in the 2200 block of North Milwaukee Avenue in the Logan Square neighborhood.

• A 24-year-old man was shot and wounded in the neck around 1:50 a.m. Sunday as he sat on the front steps of a house in the 5200 block of West Quincy Street, in the South Austin neighborhood. The gunman was driving past in a light-colored sedan, police said.

The victim was taken to Mount Sinai Hospital in serious condition.

• Around 7 minutes later, a 27-year-old man was shot and wounded in the 1500 block of South Pulaski Road in the North Lawndale neighborhood. He heard shots, and noticed he had been wounded in the abdomen, police said.

• Around 10 p.m. Saturday, two men were shot and wounded as they stood on the sidewalk in the 1400 block of East 67th Street, on the cusp of the Woodlawn and Grand Crossing neighborhoods, when someone in a passing vehicle opened fire.

One of the men, 21, was shot in the right leg and was taken to Northwestern Memorial Hospital in serious condition, while the other, 33, was shot in both thighs and was reported in stable condition in the hospital.

The victim was also taken to Mount Sinai in serious condition.

• Just after 2 a.m. Saturday, a 33-year-old man was shot and wounded as he walked in the 6000 block of South Racine Avenue in the Englewood neighborhood. He heard shots and felt pain, and was taken in serious condition to Stroger Hospital of Cook County.

• A man was shot in the hand early Saturday during a robbery in the North Lawndale neighborhood. The 23-year-old victim was walking in the 1500 block of South Millard Avenue around 12:30 a.m. when he was approached by another man who pulled out a gun and demanded money, police said.

The gunman fired several shots and wounded the man in the hand. He was taken to Mount Sinai Hospital in good condition.

With the exception of the suspect accused of shooting the police officer, and the robber who was shot, no one was in custody in any of the shootings as of Monday morning.

The Sun-Times Media Wire contributed to this report.