(CNN)Mass shootings and gun violence took the lives of at least 16 people with multiple people wounded across the United States last weekend.
Gun violence leaves fatalities in Chicago, Portland, Miami-Dade and other cities
Five people were killed in a weekend of violence in Chicago while eight people were killed in mass shootings in Oregon, Indiana, Utah, and Michigan. A high school student was killed in New Jersey and two people were killed early Monday morning in Florida.
Eight people were wounded at a graduation party in Cleveland. In New Orleans, eight people were injured in a single shooting incident. Five people were wounded in a shooting in Oakland.
CNN defines a mass shooting as an incident that results in four or more casualties (dead or wounded) excluding the shooter(s).
In a Monday news conference, Chicago Police Superintendent David Brown said murders in the city are up 5% and shootings are up 17% compared to this date a year ago.
"Much of the violence that we have seen over this weekend and throughout the year is driven by a gang culture. Gang culture of retaliation and revenge. Some call it street justice," Brown said.
Fifty-five people were shot in 41 incidents in Chicago between 6 p.m. Friday and 11:59 p.m. Sunday, according to Chicago Police Department (CPD) spokesperson Kellie Bartoli.
In the five separate fatal shooting incidents in Chicago, nobody has been taken into custody, according to CPD.
Eight people were wounded Sunday morning in the 8900 block of South Cottage Grove after occupants in a silver sedan fired into a group of people standing on a sidewalk, according to CPD. Six men and two women ranging from 28 to 38 years old were hit by gunfire and transported to local hospitals. The suspects remain at large.
In a separate incident, an individual in a car shot at a 34-year-old man standing on a porch, striking the man in his leg, according to CPD.
Separately, a 24-year-old man was asleep when "shots were fired from outside that went through the drywall and struck him twice in the leg," police said.
In both those cases, the shooting victims survived their wounds.
The weekend of violence comes as the CPD reported the lowest number of murders over Memorial Day weekend in 10 years.
More than 8,400 people have died from gun violence in the United States this year, according to the Gun Violence Archive, with over 240 mass shootings as of June 1. In May, the archive told CNN there had been a 23% uptick in deaths from gun violence so far this year.
In Portland, Oregon, police officers responded to a report of a shooting at a residence on Southeast Boise Street around 10:25 p.m. Sunday and discovered four people dead from gunshot wounds, according to a statement from the Portland Police Bureau.
Portland homicide detectives are investigating and have asked the public to assist with any germane information regarding the incident. The exact manner of death is pending an autopsy, according to police.
No information on arrests was available.
In Florida, at least two people including a 15-year-old boy were killed in an early Monday morning shooting in Miami-Dade County, according to a news release from Miami-Dade Police.
Police responded to a call of shots fired just before 2 a.m. Monday and found five people with apparent gunshot wounds, including the two who died, the release stated.
Two additional juveniles were airlifted to Kendall Regional Medical Center and were in critical and stable conditions, police said. A fifth victim was transported to Jackson South Medical Center in stable condition.
Officers located the gunman, who was identified as the deceased female's boyfriend. As officers were attempting to establish communication with the suspect, he was found dead from a self-inflicted gunshot wound, police said.
Police have not released any additional details regarding a motive, only calling this shooting "domestic related."
Police did not provide suspect information and the investigation is ongoing.
In Indianapolis, Indiana, a Saturday shooting left two people dead and two injured, the Indianapolis Metropolitan Police Department said. The shooting happened in a parking lot after the victims left a business, a press release said.
Officers responded to a report of shots fired just after 2 a.m. and found four people suffering from gunshot wounds, according to the release.
One man was pronounced dead at the scene. Another man was transported to a hospital in critical condition and later died of his injuries, the release said.
Two other people, an adult male and adult female, were taken to hospitals and remain in stable condition, according to the release.
In Salt Lake City, Utah, a shooting left one person dead and four others injured Sunday morning, said city police Lt. Carlos Valencia.
Police responded to a call of shots fired with reports of "multiple people laying on the grass" and found five people who had been shot, Valencia said.
Four of the victims were taken to the hospital in critical condition and are now listed in stable condition, Valencia told CNN. The fifth victim was pronounced dead at the scene.
Police believe the shots originated from a passing car, but no suspect information or possible motive was available, Valencia said.
In New Jersey, an 18-year-old male was killed and another male teenager was injured in a shooting near a high school in Maplewood on Sunday night, said Ronald Taylor, the South Orange & Maplewood School District superintendent of schools. Both were students at Columbia High School, Taylor said.
The shooting occurred at Columbia High School's sports complex around 9:38 p.m., according to a news release from the Essex County Prosecutor's office.
In Fruitport, Michigan, one person died and three were injured in a shooting late Friday night, Fruitport Township Police said in a Nixle alert.
Police said three people were injured and the fourth person passed away at the scene.
In Cleveland, at least eight people were hospitalized following a Sunday night shooting on the city's westside, Detective Alexander Sinclair with the Cleveland Police Department told CNN.
The shooting happened around 10 p.m. at a graduation party being held in the 3700 block of Woodbridge Avenue, police said.
The exact conditions of the injured are unknown, but police said four of the victims were taken into surgery after they arrived at the hospital. Sinclair said he didn't know of any fatalities.
Based on preliminary information, police believe the suspect or suspects drove up to the party and began shooting. Police have not released any information on suspects or motive.
In New Orleans, at least eight people were injured in a shooting early Sunday morning, the city's police department said in a tweet.
All of the victims were taken to hospitals, with one female in critical condition after suffering a gunshot wound to the face, a tweet said. The other victims are in stable condition or received only graze wounds.
A shooting in Oakland, California, left five adult males injured on Sunday, according to a statement from the Oakland Police Department. No information is available on motive or suspects at this time from Oakland police
Four teenaged men were shot outside of a Hooters in St. Louis on Sunday morning, then self-transported to an area hospital for treatment, according to a statement from the St. Louis Metropolitan Police Department.
According to the statement, a preliminary investigation reveals three suspects armed with assault rifles fired gunshots at the victims as they were outside the Hooters.
In North Carolina, Sheriff Lemmie Smith with the Greene County Sheriff's Office told CNN "it was a party that got out of hand" at a mobile home park that led to four people getting shot early Sunday morning.
Three of the gunshot victims have been treated and released from an area hospital, and one remains in intensive care. There are no suspects currently.