Redwood City man arrested in mason's homicide in Los Altos

Police on Monday said they arrested a man over the weekend for the fatal shooting of a mason in Los Altos that happened last week. 

The victim, Roberto Riviera, 48, of Union City was shot and killed on May 4 while working in the backyard of a home on Highland Circle. 

Edgar Lainez-Portillo, 25, of Redwood City is now under arrest for his suspected involvement in the shooting. 

Police have not released a motive or said whether the two men knew each other. 

Police said this was the first homicide in Los Altos since 1994.