SAN MATEO — The San Mateo County coroner’s office has identified a 66-year-old woman fatally beaten with a baseball bat by her neighbor in San Mateo last weekend as Ellen Mackay.

Brenda Martinez reportedly beat Mackay to death with the baseball bat at a residence in the first block of North Claremont Street, San Mateo police said.

At about 8:30 p.m. Saturday, Martinez went to the Police Department to report the homicide and implicated herself as the suspect in Mackay’s death, according to police.SAN MATEO WOMAN KILLED WITH BASEBALL BAT

Mackay was found inside the home with head trauma and was pronounced dead at the scene. The baseball bat was recovered as evidence, police said.

Martinez was arrested on suspicion of homicide.

According to San Mateo County Chief Deputy District Attorney Karen Guidotti, Martinez has not yet been charged in the case.