Rashon Abernathy is the one prosecutors say shot and killed Mission Beach teenager Garrett Berki during a robbery that began with a fake ad on Craigslist.
In that robbery, Berki wanted to buy a computer, instead he and his girlfriend were robbed by three suspects.
Berki was then allegedly shot by Abernathy when he tried to follow the suspects in his car.
According to a search warrant, Abernathy, 17, is now a primary suspect in a similar robbery on May 5, about a week before Berki was killed.
In the earlier case, a victim says he had answered an ad for a MacBookPro, the same computer that had attracted Berki's interest.
The victim agreed to meet the seller at Paradise Hills Park, but the victim was confronted by two teenagers.
The teens allegedly took $600 in cash. When the victim began to chase them on foot, one of suspects pointed a gun at him police said.
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The victim has now positively identified that armed suspect as Rashon Abernathy investigators said.
Detectives also say Abernathy and other fellow gang members posted several items on Craigslist, including $4,000 diamond earrings.
Investigators say an accomplice of Abernathy met a buyer interested in the earrings and beat the buyer before robbing him of $1500 in cash and stealing his car.
Former City prosecutor Anthony Solare believes these other cases could be included in an upcoming trial.
"Because that's going to show this person has been involved in this activity and create a much darker picture of the people involved," Solare said.
Abernathy is charged with murder and two counts of robbery. His bail has been set at $5 million.
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