Sources say investigators have confirmed that a series of homicides in west Phoenix are connected, and a person or group is likely behind them all.

Last week, the Phoenix Police Department warned those living in an area roughly between 51st and 75th avenues and Camelback and McDowell roads of a recent increase in the number of deadly shootings.

See a map of the shooting locations below.

The majority of the shootings happened earlier this month, though police said one that is connected happened in April.

Police have no suspect information in the shooting of 21-year-old Diego Verdugo-Sanchez, who was killed April 1 by a suspect who shot at him from inside a vehicle near 55th and Campbell avenues.

Horacio De Jesus Pena was shot and killed on June 3 near 67th Avenue and Thomas Road after returning home from work. No suspect information is known.

Detectives are also looking for information in the murder of Manuel Garcia near 67th Avenue and McDowell Road. The 19-year-old was in his car when another vehicle approached and, after a brief conversation, the suspect opened fire.

The fourth shooting left 31-year-old Angela Linner and 12-year-old Maleah Ellis dead in their car near 63rd Avenue and McDowell Road. A third victim remains in critical condition. Police said witness reported seeing a suspect leaving the area in a light-colored sedan. He is described as a Hispanic male, 30 to 35 years old, medium build, wearing red shorts and a white t-shirt, armed with a semi-automatic gun.

Sources did not have any information on the identity of the person or people wanted in connection with the homicides or if there had been any arrests in connection with the four cases.