A baby girl was found dead in a dumpster in a Southern California beach community on Sunday, the San Diego Union-Tribune reported.

While looking through trash behind an Imperial Beach, California, strip mall, a person discovered the body of 3-week-old Eliza Delacruz, police said.

The infant was in a plastic bag, which also contained trash, homicide Lt. John Maryon told the newspaper. Delacruz's parents and uncle, the brother of the baby's father, had been shot at a Long Beach, California, home on Saturday evening; the 10-pound baby had been declared missing after the incident.

Authorities are now looking for a male suspect, the Los Angeles Times noted, and are offering a $1,000 reward for information leading to an arrest in the case.

"The preliminary investigation leads detectives to believe an adult male suspect fled with the infant immediately after the shooting occurred," the San Diego Sheriff's Department detailed in a statement.

Delacruz's mother and uncle remained hospitalized as a result of the shooting, the San Diego Union-Tribune said; as of Sunday afternoon, they were in critical but stable condition. The baby's father, meanwhile, had been released after receiving medical treatment.

Police said they have not established a motive for Saturday's attack, the newspaper noted. However, authorities do not believe the incident marked a random act of violence.

The body found in Imperial Beach was identified as belonging to Eliza Delacruz by the San Diego County Coroner's office, the Associated Press said. The agency did not immediately reveal the cause of death.

Long Beach Police described Delacruz's death and the shooting of her relatives as "heinous" and "horrific" crimes, according to the Los Angeles Times. The search for the suspect believed to be behind the gunfire and the baby's abduction began shortly after 6 p.m. Saturday, when officers responded to a call at a home in North Long Beach, they detailed.

Officials are urging individuals with information about the case to contact the department at (562) 435-6711; an anonymous tip line is also available at (800) 222-TIPS.