The Independent Police Review Authority is investigating three police-involved shootings in Chicago.

Police officers shot three people over 18 hours across Chicago Friday, including a 14-year-old boy who died.

Police said they found guns at two of the scenes and, in the third incident, were threatened by a man who claimed to have a gun but did not.

The most recent shooting happened at Cicero and Berenice avenues in the Old Irving Park neighborhood about 9:50 p.m. Friday. The victim was identified by the Cook County medical examiner's office as 14-year-old Pedro Rios, of the 7400 block of North Ashland Avenue.

It happened just east of Cicero Avenue.  Officers saw a young man crossing Cicero heading east with something sticking out of his waistband and tried to stop him, police said.

The young man took off running and then pointed a "a large revolver" at pursuing officers, according to a statement released by the police department.

"It turned out to be a .44 caliber revolver with an 8- or 10-inch barrel," Fraternal Order of Police spokesman Pat Camden said. "A Dirty Harry-looking gun."

Officers fired and hit him, police said. He was pronounced dead about 10:10 p.m., according to the medical examiner's office, which did not release his name immediately.

The first police shooting Friday occurred around 4 a.m. when an officer wounded a man during a chase down an alley in Englewood, authorities said.

Police had responded to a 911 call of a man with a gun at 74th Street and Princeton Avenue, Camden said. When a beat car pulled up, Dominiq Greer, 23, ran off and an officer chased him into an alley just east of Vincennes Avenue and north of 75th Street, he said.

Greer threw the gun while fleeing police, causing it to discharge, according to Cook County court records. A police officer returned fire, according to prosecutors.

Greer remained hospitalized Sunday. He was charged with unauthorized use of a weapon by a felon and ordered held on $150,000 bail.

Police took a gun into evidence from the scene, according to Camden. “That’s the one guarantee in life. You shoot at police, they’re gonna shoot back,” he said.

Later in the morning, around 11:25 a.m., police shot and wounded a man in the 1500 block of West Birchwood Avenue in Rogers Park, officials said. 

A police statement said Rogers Park plainclothes officers were on patrol when they saw Lavail Smith, 45, "drinking on the public way. As officers approached to conduct a field interview, the offender fled on foot.

"The officers gave chase as the offender ran through an apartment complex and forced entry into an occupied residence," the statement said. "Officers continued to pursue and were confronted by the offender in a backyard gangway area.  At this point, the offender stopped and yelled, 'I have a gun, you’ll have to shoot me,' while simultaneously reaching for his waistband and turning towards the officers.

"Pursuing officers, fearing for their lives and that of their partners, fired at the offender, wounding him," the statement said. The man turned out not to have a gun, police said.

Smith, of the 1500 block of West Fargo Avenue, was taken in serious to critical condition to Presence Saint Francis Hospital in Evanston, according to Fire Department spokesman Larry Langford and Cook County court records.

He faces a felony criminal trespass to residence charge, and misdemeanor aggravated assault, battery and resisting charges, as well as a citation for drinking in public, according to court records. Greer remained hospitalized Sunday, charged with unauthorized use of a weapon by a felon and ordered held on $150,000 bail.

Camden said Smith was wearing an electronic monitoring bracelet on his ankle. When officers took him into custody, he was “thanking them for shooting him,’’ Camden said.

“Once you’ve labeled that threat -- 'I’ve got a gun, I’m going to shoot you' -- at that point you have to assume the worst case scenario,’’ Camden said.

All three shootings are being investigated by the Independent Police Review Authority, which is routine.

chicagobreaking@tribune.com | Twitter: @ChicagoBreaking