Man arrested after shooting spree leaves 4 dead, 1 injured in Arizona over the weekend

Five separate shootings over the weekend in Arizona that left four dead and one injured led to a man being arrested and charged with murder, according to police.

The shootings took place from Friday through Saturday in Mesa and Phoenix, police said.

Iren Byers, 20, was arrested and charged Sunday with four counts of first-degree murder and one count of attempted first-degree murder for his role in the shootings, according to a news release from the Mesa Police Department.

Byers is believed to be "solely responsible" for all the shootings, the department said. He "took responsibility" for the shooting spree during questioning, according to the release.

Byers has received a visit from an on-call attorney with the Maricopa County Office of the Public Defender, Amanda Martin, the Capital Unit Attorney Supervisor for the office, told CNN via phone. An attorney from the office will be assigned to represent Byers.

The string of violence began Friday afternoon, according to a news release from the Phoenix Police Department. Nicholas Arnstad, 41, was fatally shot near a canal in Phoenix, police reported.

Julian Cox, 41, was found dead Friday night in Beverly Park, according to the Mesa Police Department. While at the park in the early hours of Saturday morning, officers heard shots nearby and discovered Angela Fonseca, 36, who was hospitalized for gunshot injuries.

Then, just before 1 a.m., police discovered the body of Stephen Young, 41, killed near a Greyhound bus station. While searching the area, police found the body of John Swain, 40, just after 2 a.m.

Phoenix police worked with Mesa police to determine the same shooter was involved in all five incidents, based on the 9 mm gun used in the shootings, the suspect's clothing, and his physical description, according to the probable cause statement.

The suspect was arrested on an unrelated charge and admitted to shooting the five people and not calling for aid for any of them because he didn't feel like they deserved the aid, according to the probable cause statement. Myers also told police where to find the clothing he wore during the shootings and the gun he used, according to the statement.

"We are saddened for the families of these four victims," Det. Brandi George of the Mesa Police Department told CNN in an email. "Knowing that Iren Byers will have to face the consequences of his unjustified actions is the start of justice to be seen."

Byers was booked and is being held without bond, Mesa Police said.