Wideman, who lived nearby on the 700 block of East Willard Street, died a short time later at Temple University Hospital.
Investigators have not said if they have determined why Wideman was stabbed.
Anthony Ginns, 28, was shot in the head while sitting inside a minivan about 6:50 p.m. Saturday on the 2500 block of South Sartain Street in South Philadelphia, police said.
Ginns, who lived on the 800 block of North 11th Street in North Philadelphia, died at 7:07 p.m. at Temple University Hospital, police said.
Again, no word on a possible motive.
At about 10:20 p.m. Saturday, police responding to a report of a person with a gun found Whitcomb Rogers, 37, shot several times on the 2700 block of Vare Avenue in South Philadelphia's Southbrook Park neighborhood.
Rogers, who lived on the 500 block of McClellan Street in Southwark, was pronounced dead at Hahnemann University Hospital at 10:40 p.m.
Why Rogers was shot is not clear yet.
Shortly after 2 a.m. Sunday, police found Robert Williams, 22, in a home on the 1500 block of Federal Street in Point Breeze with gunshot wounds to his left side and upper right back.
Williams, of Yeadon, was pronounced dead at Thomas Jefferson University Hospital at 2:34 a.m.
Police said the shooting grew out of an argument, the nature of which they did not spell out.