State police have charged the younger brother of suspected serial burglar Justin P. Weissinger with breaking into two homes in Lyme within one week last spring and stealing jewelry and other items worth approximately $170,000.

Karl W. Weissinger, 21, was arrested Wednesday morning and charged with multiple counts of burglary, larceny, conspiracy and criminal mischief. He was held in lieu of a $150,000 bond and is expected to be arraigned Friday in New London Superior Court.

The Weissinger brothers, who grew up in Old Lyme, have been connected to burglaries from Chester to Salem through high-end jewelry, precious metals and antiques that they allegedly sold to a Mystic jewelry dealer over several months.

The arrest warrant affidavits in the Lyme cases, prepared by state Trooper Gary W. Inglis, involve a March 28, 2012, burglary on Cove Road and an April 4, 2012, break-in on Bill Hill Road.

In the Cove Road burglary, the house was entered through a second-floor window while the homeowner was out of state. The burglars disabled the alarm system by tearing the unit off the wall, entered a cedar closet and pried a safe off the wall and stole sterling silver items from a dining room hutch.

One of the items stolen was a 2.36-carat diamond, appraised at $20,000, that was recovered from a New York auction house, according to the court document.

The burglars appeared to have entered the Bill Hill Road residence through the basement while the home owner was at work, according to the court document. Troopers discovered that one door had been vandalized but that someone had placed a piece of black electrical tape on an interior door knob to allow the lock on the door to malfunction. The thieves took $80,000 worth of jewelry from a bedroom, according to the affidavit.

Troopers had been investigating a series of burglaries in the area when they turned their attention to Justin Weissinger, 25, a former Marine who had been convicted of burglaries he committed while stationed at Camp Pendleton in California.

Justin Weissinger was found with a .380-caliber pistol stolen from a Salem home after he was pulled over in July following a high-speed chase in Montville. He has remained incarcerated since his arrest and earlier this week was served with additional arrest warrants.

Two days after the high-speed chase, troopers executed a search-and-seizure warrant at a barn on the Brush Hill Road, Lyme, property of former First Selectman William T. Koch Jr., who is the boyfriend of Weissinger's mother, Nicole Weissinger.

Justin Weissinger didn't live at the Koch home but used the barn for various projects, according to Koch.

The ongoing probe led Inglis, the state trooper, to the Goldsmiths & Silversmiths Co. jewelry store at 9 W. Main St. in Mystic. Inglis went to the store on July 24 and ran into Karl Weissinger, who was attempting to sell two stolen watches and a gold chain, according to the court documents.

Matthew Hopkins, owner of the jewelry store, said the brothers had visited the store about 15 to 25 times, with jewelry, precious metals and antiques for sale, according to state police.

Hopkins said Justin Weissinger told him that he and his brother acquired the items by bidding on and buying abandoned storage lockers.

"I thought it sounded plausible because I have seen it on television shows," Hopkins told the troopers. "At the time, I was very happy for them."

Hopkins, who met with state police and turned over stolen goods he said he had bought from the brothers, provided financial records indicating he paid them about $80,000, according to the court documents.

Justin Weissinger was interested in smelting his own gold and silver, and Hopkins said he gave him pointers. One day, he said, the brothers came into the store together with several items. Karl Weissinger produced a cut piece of Scheibler silver that Hopkins thought was from a pendant. Hopkins said he told Karl Weissinger it was a beautiful and valuable piece and that he shouldn't have cut it.

"Karl looked remorseful and Justin poked fun at him," Hopkins told the troopers.

Hopkins said he was led to believe the brothers were working as partners and splitting the proceeds.

Hopkins opened up the store to Lyme and Old Lyme area burglary victims afterhours and turned over to state police the items that they identified as theirs, according to the affidavit. One of those items included a gold chain that had been stolen from a residence on Johnny Cake Hill Road in Old Lyme.

The troopers also recovered, from Justin Weissinger, a gold Krugerrand coin on a chain that had been reported stolen from a Library Lane residence in November 2011. Hopkins told the troopers he had seen Justin Weissinger wearing the chain and had offered to buy it but that Weissinger had refused.

"My impression is that it was special to him," Hopkins told the troopers.

State police Sgt. John Mesham, who is supervising the investigation, said more arrests are expected.

Karl Weissinger is being held at the Corrigan-Radgowski Correctional Center pending his court appearance on Friday. Justin Weissinger also is being held at Corrigan. In addition to the mounting charges he faces here, court officials say he is expected to be returned to California at some point to face violation of probation charges in that state, where he was convicted of burglary.

Weissinger, who was discharged from the Marines, is a key witness in a high-profile home invasion/murder of a Marine sergeant and his wife. Weissinger was locked up on the burglary charges when four fellow Marines allegedly carried out the crimes. He said one of the Marines, with whom he had committed several burglaries, confided in him with the details.

k.florin@theday.com