A man was shot to death in Hayward on Sunday night, just days after a separate shooting that claimed the life of a jewelry store owner, a police spokesman said.

Sunday night's shooting was reported at 10:40 p.m. at an apartment complex at 24545 O'Neil Ave., police Sgt. Eric Krimm said.

Krimm said the victim, a 43-year-old man, was shot near the doorway to his third-floor apartment.

The wounded victim made his way to the first floor and pulled the building's fire alarm, Krimm said. When the alarm sounded, a resident on that floor stepped outside, found the victim and called 911.

The victim was taken to a hospital, where he died. His name has not yet been released.

Krimm said there was a "personal marijuana grow" inside the victim's apartment and that police are looking into the possibility that the shooting was drug-motivated. It has not yet been determined whether the grow was legal, he said.

The shooting came three days after Ramiro Espinoza, 53, the owner of Espinoza Jewelry and Boutique at 655 W. Tennyson Road, was killed at his business.

Police responded to a 911 hangup call at 3:50 p.m. and found Espinoza shot, Krimm said. He was pronounced dead at the scene.

The circumstances of the shooting are still unclear, and police are investigating whether it was related to a robbery attempt, Krimm said.

"We really don't know what the motive behind it was," he said.

Police are working with the family to determine whether anything was taken from the store.

Espinoza was working alone at the time he was killed, and police believe it may have been Espinoza himself who called 911, Krimm said.

Hayward police are also investigating a third shooting that wounded two men at a condominium complex on Saturday night, Krimm said. That shooting occurred at about 10:30 a.m. in the 27400 block of Ponderosa Court.

Krimm said a man who lives at the complex arrived home in a car containing three other people -- another man and two women. He got out of the car and was walking to his home when he heard gunshots and was hit in the back, Krimm said.

The second man, who was still in the car, was shot multiple times.

Both were taken to hospitals and are expected to survive.

The suspects were described as two males, but no arrests have been made in the case.

All of the shootings remain under investigation. Anyone with information about them is asked to call Hayward police at (510) 293-7033. Tips can also be called in to Inspector Ritchie at (510) 293-7219 or Detective Hoyer at (510) 293-7172.