The San Francisco police department is investigating four separate shootings since the Fourth of July that left four men dead, but so far, no suspects appear to have emerged.

At around 10 p.m. on Friday, July 4th, 49-year-old Wesley Willis was inside a vehicle near Harbor Road and Ingalls Street in Hunter's Point when he was shot where he sat. According to SFPD spokesperson Sergeant Danielle Newman, Willis was transported to San Francisco General Hospital, where he succumbed to his injuries.

Then, at 2:54 a.m. on Sunday, July 5th Antonio Cortez, age 37, was standing with another man in front of a home in the 1700 block of La Salle Avenue in the Bayview, when someone opened fire at them, Newman says. Cortez was transported to SF General, where he pronounced dead about three hours later. The other victim of that shooting, a 49-year-old man, has been hospitalized with life-threatening injuries.

In the third fatal shooting, at around 3 a.m. this morning, a man believed to be in his 20s was shot and killed on Brookdale Avenue in the Sunnydale public housing complex, close to the Visitacion Valley site where outreach counselor and former gang member Allen Calloway was shot and killed as he played with a bunch of kids on Friday, June 17. (According to SFPD, no suspects have been identified in Calloway's death.)

Newman says that another fatal shooting was reported at 9:30 a.m. in the first block of Ironwood Way in Hunters Point.

The SF medical examiner's office has yet to identify either of the victims of this morning's homicides, and SFPD have not released any information on suspects in any of the slayings.

According to Newman, Friday's fatal shooting was San Francisco's 15th homicide, making Monday's the 16th, and the two this morning the 17th and 18th. At this time last year, SFPD says San Francisco had had 22 homicides. In 2012, we had 38.