SAN DIEGO (CNS) - Five people, including four gang members, were charged Friday with an early morning home-invasion robbery in Sorrento Valley in which a mother of three was attacked as she slept and sexually assaulted.

Stephen Ramon Gomez, 20, Thomas James Smith, 24, and brothers Aaron David Rico III, 20, and 17-year-old Aaron David Rico V were charged with conspiracy to commit burglary, robbery, burglary and sexual assault. All four are gang members, said Deputy District Attorney Jalyn Wang.

Robin Elizabeth Shawver, 20, faces conspiracy, robbery and burglary counts.

The arraignment follows Thursday's announcement by police that six people were arrested in connection with a series of residential robberies during which some victims were tied up and threatened with guns in their northern San Diego homes.

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One person arrested Thursday in connection with the crime spree, 19-year- old Victor Fransisco Harvey, was not charged in Friday's case.

Wang said the charges filed Friday stem from only the Jan. 31 home-invasion robbery in Sorrento Valley.

The investigation is continuing and more charges may be forthcoming against the defendants charged Friday or other defendants, Wang told reporters.

In the Jan. 31 incident, Wang said the victim and her three children -- ages 4-8 years old -- were asleep about 2 a.m. when the defendants came into the home through an unlocked door, barged into her room, demanded money and asked where the safe was located.

The defendants took jewelry off the woman's body, pointed a gun at her and threatened to shoot her, then sexually assaulted her, covered her face with a pillow case, tied her up and fled with $10,000 worth of jewelry and other property, the prosecutor said.

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Judge Jay Bloom called the case ``extremely serious'' and set bail for Gomez, Rico III, Smith and Rico V at $1 million each. Shawver's bail was set at $500,000.

Smith -- who was on probation for residential burglary -- faces 60 years to life in prison if convicted. Gomez and the Rico brothers face 25 years to life if convicted. Shawver faces nine years behind bars if she's found guilty.

"This is a very serious case,'' Wang said outside court. "This is a very violent act that these defendants committed. The victim was traumatized by what happened."

The most recent of the crimes occurred in the 14000 block of Breezeway Place near Cedarhurst Lane shortly before 5:30 a.m. on Feb. 11, according to police. It took place about five miles from where a trio of thieves entered a home in the 11300 block of Spring Meadow Lane through a side door less than three hours earlier.

The suspects also have been linked to a similar robbery that took place in the 11400 block of Aliento Court in Rancho Bernardo on Feb. 5.

While conducting searches as part of the investigation, detectives impounded two replica guns believed to have been used during the robberies, police said.

A status conference was set for Feb. 25 and a preliminary hearing for March 3.