The arrest came after someone called police around 3:10 p.m. last Thursday and reported a suspicious man walking near Larch Avenue and Wandel Drive, according to police.
Officers spoke to the man, who said he had been painting at a nearby home.
Police said a consensual search turned up some jewelry in the man's lunchbox.
The man was detained after police found his explanation for having the jewelry to be inconsistent, police said.
Later police contacted the elderly woman who had hired the man to paint her house and showed her the jewelry, which she identified as her own. She said the jewels had been stolen when she was out of the house, police said.
Based on probable cause, police arrested the man, identified as 21-year-old Hector Mauricio Salazar, on suspicion of possession of stolen property and burglary.
The Contra Costa County District Attorney's Office charged Salazar earlier this week with felony grand theft, possession of stolen property and financial elder abuse, according to Moraga police Chief Robert Priebe.
Salazar has a prior robbery conviction in connection with an Alameda County case last year, police said.
