Five people have now been charged with murder and other offenses in a shooting death near a North Philadelphia playground, the city's second homicide of 2015.

Separately, police on Monday also identified the victims in the third and fourth killings in the city this year and said investigators are continuing to seek suspects in those slayings.

Philadelphia police said Monday that five suspects have been arrested in the slaying of 24-year-old Gerald Sawyer, who was shot in the head about 11:20 p.m. Friday.

Officers found Sawyer, of the 2900 block of West Arizona Street, near a park at North 29th Street and Chalmers Avenue.

Police said 24-year-old Harold Boyer, of the 4100 block of Greeby Street, was identified as the gunman in the killing.

Also charged with murder, conspiracy and other offenses in Sawyer's killing are: Tameca Rivera-Griffin, 34, of the 1600 block of South Napa Street; Semaj Lemar, 19, of the 2200 block of Bridge Street; Fatima Moses, 26, of the 1600 block of South Napa Street; and Wayne Brown-Griffin, 21, of the 2600 block of West Sterner Street.

The arrests of Boyer, Rivera-Griffin and Lemar were first announced Sunday, while investigators said they were looking for Brown-Griffin. Moses' alleged role in the slaying hadn't previously been disclosed.

Investigators have not yet disclosed a motive for the killing.

Police on Monday also identified victims in two weekend homicides, the city's third and fourth of the year.

Mijael Rodriguez-Ramirez, a driver for a car and limousine company, was found fatally shot inside a 2007 Chrysler 300 on the 5400 block of Delancey Street in West Philadelphia on Saturday night.

Officers found the 24-year-old from the 100 block of East Sterner Street in the driver's seat at 7:10 p.m. and he was pronounced dead at the scene, police said.

Police said 39-year-old Bernard Ray was the victim of an early Sunday morning slaying in Hunting Park.

Ray, of the 6100 block of Yocum Street, was found in a Ford Windstar, suffering from a gunshot wound to the chest, after the vehicle crashed into three parked vehicles on the 3700 block of Delhi Street just after 3 a.m. Sunday.

Ray was pronounced dead at the scene.

No arrests have been made in the slayings of Rodriguez-Ramirez and Ray. A $20,000 reward for information that leads to an arrest and conviction is offered in all Philadelphia homicide cases.

The first homicide victim of 2015 was 18-year-old Hyneaf Harris, who was shot to death in the basement of his residence on the 5800 block of North Philip Street at about 5:15 a.m. Thursday. A 16-year-old, Jahkere Moore, has been charged as an adult with murder and other offenses in that slaying, according to police.