(AP) GREELEY, Colo. Police arrested four people early Tuesday as part of their investigation into the slaying of an 18-year-old mother at a Greeley park over the weekend.
Jorge Zamora, 23, and Carlos Valenzuela, 18, were arrested on suspicion of first-degree murder, police spokesman Sgt. Joe Tymkowych said.
Also arrested as alleged accomplices were Enrique Ramirez, 20, and Barbara Sue Salinas, 18, police said.
Sylvia Santillan, a mother of a 2-year-old girl and 10-month-old boy, was shot Sunday night at Greeley's Island Grove Regional Park.
"I got the call at home and rushed to the hospital," said her brother, Jaime Santillan. "But she died before we could talk to her."
Police said an argument led to fights and the shooting.
"She was in the wrong place at the wrong time," said her sister-in-law, Rebecca Santillan.
Family members said they believe Santillan was killed by gang members. Two years ago, Greeley had six gang-related homicides.
At the Santillan home on Monday, dozens of friends and family members gathered to show support for the victim's parents.
Her brother, Jaime, spoke for the family: "Sylvia was a very outgoing, independent woman and a good mother. She graduated from the Aims High School Program in 2005, and she had a good job and an apartment for her kids. She was just a good person."