Four were killed and one critically injured during a brutal weekend.The Schuylkill Expressway was shut down for three hours this morning after a driver was shot and killed. State police said the victim was traveling eastbound near the Montgomery Avenue exit of I-76 around 2:50 a.m. when another car drove up alongside and fired numerous bullets through the passenger side, killing the driver.The victim has been identified at Kareem El, 29, of Philadelphia. Police say he was likely targeted.A four-year-old is in critical condition after he accidentally shothimself in the chest with a .38 caliber gun he found under his mother's pillow. Theincident happened yesterday around 7 p.m. Saturday on the 6200 block of CardiffStreet in Mayfair.The child was rushed to St. Christopher's Hospital, wherehe underwent surgery and was placed in critical condition. No charges have beenfiled at this time.Officers found Montague White, 26, lying in the street at 4000 Cedar Grove Drive in Fairmount Park around 6 a.m. Saturday. The man suffered from multiple gunshot wounds to the chest and hip and died on the scene. Police said the motive was an argument.A man and a woman were fatally shot around 1:40 a.m. Friday morning atThe Corral Bar on the 5200 block of Market Street in West Philadelphia. Crystal Shadding, 43,died on the scene and Troy Wimberly, 38, died less than an hour later at the Hospital ofthe University of Pennsylvania.No arrests have been made.