Newly obtained evidence photos show the $300,000 worth of diamonds that a former California state worker has been convicted of stealing while on the job.Miguel Espinosa, 60, pleaded guilty to three counts of grand theft for stealing the jewels and other valuables while he worked in the mailroom at the State Controller’s Office.The state agency safeguards unclaimed property, belongings that have been left behind in safe deposit boxes after someone died or didn't pay the bill for example. Things that are supposed to be returned when the rightful owner or heir turns up, like in the case of a Southern California man in March last year."The items were mailed to him, and then that's when he opened the package. He noticed there were items missing," California Highway Patrol Officer Anthony Ruiz said.He reported that five of his diamonds were not included in the package he received from the State Controller’s Office.The agency denied requests to discuss this case with KCRA 3 Investigates, but CHP said the State Controller's Office checked its surveillance cameras to find out what happened. The office traced the package's movements in the mailroom. "That’s when they discovered that there was suspicious behavior by one of the employees," Ruiz said.Espinosa’s behavior caught their attention. "He was taking the box to a location where there were no cameras. He was bringing it back, re-taping it and then sending it off," Ruiz said.CHP got a warrant to search Espinosa's Sacramento house. However, Ruiz knew it was a long shot. It had already been a month since the theft. The diamonds could be anywhere —sold or carefully concealed. "It’s not my house. I don't know the hiding spot. So, you know, I felt like we had a huge task to really find 'em," Ruiz said.He said he detained Espinosa while another officer checked the suspect's room, looking first under the bed. "There was a bed with sort of a cabinet underneath, and he had just opened the cabinet, and they were right there," Ruiz said. "It was very, very simple."It didn’t stop there. Officers found hundreds of items they gathered as evidence from jewelry to valuable coins and bars of silver."Things that looked like family heirlooms," Ruiz said. Everything had to be carefully cataloged. It took days, generating more than 300 photos. See photos of some of the evidence here, here, here and here. "The volume was massive," Ruiz said.It went from an investigation involving one victim to 12 potential victims, Ruiz said.Investigators believe the items were stolen over at least a seven-year span.(Photo gallery below: Diamonds, coins among the items that were taken.)It was precious property that, in some cases, people were supposed to inherit after the death of a grandmother, a sister or a father. "There was one lady, her son lives here in California, and she lives in Iran. And she had this sort of specialty, like, gold purse," Ruiz said. "She couldn't believe it. She thought that her dad, like, sold it."With a gold mine of evidence, the case went to the Sacramento County District Attorney's Office. "We’re in the special investigations unit," Deputy District Attorney Nicholas Johnson said.The unit handles high-level government crimes. "In this case, there was a government employee who took advantage of a situation in which he was entrusted to maintain people's property," Johnson said. The DA’s Office charged Espinosa with 22 counts for the stolen goods. However, Espinosa ultimately pleaded guilty to just three of those charges, taking prosecutors up on a deal."This case was a particularly strong case. The evidence was overwhelming. We made an offer, and he accepted it," Johnson said, explaining that prosecutors often make offers that they feel are fair and just in order to avoid the cost and risk of taking it to trial.In April, Espinosa faced a judge for sentencing."Mr. Espinosa, I did read the letters that were attached and included in your probation packet," Sacramento County Superior Court Judge Satnam Rattu said. "One thing that stood out to me is the concept of family and how you believe in family, and what was ironic to me was the fact that you stole from families. People who had artifacts and, you know, things that they kept in their family for generations maybe that you were just taking."The judge told Espinosa that he needed to see how he hurt those families by stealing from them.He was sentenced to serve one year and eight months in county jail and another year and eight months on probation.Meanwhile, investigators said the families got their belongings back.It leaves just one thing unresolved, one last lingering question for Ruiz."Mostly it was just why he did it. He wasn't selling the property," Ruiz said.Espinosa had no criminal history up to that point, he added."Was he getting some sort of thrill out of doing it? He did it once and just kept doing it? Those are questions that I don't have the answers to," Ruiz said.Police said Espinosa never agreed to talk with them when he was arrested.KCRA Investigates also tried to reach out to Espinosa in jail, but he did not respond. Espinosa is expected to be released at the end of January 2025, according to online jail records. | MORE | How to check for unclaimed property in CaliforniaSee more coverage of top California stories here | Download our app | Subscribe to our morning newsletter