SAN MATEO, Calif. -- A suspected gunman who shot and killed a San Mateo woman in her home Tuesday morning had previous contact with his victim and stalked her via the internet prior to laying in wait at her house on the day of the fatal incident, according to authorities.

San Mateo Police gave the gunman's age and name as 22-year-old Oakland resident Raymond Gee at a press conference early Wednesday evening. San Mateo Police Chief Susan Manheimer revealed that the incident was not a random attack or home-invasion robbery as previously suspected.

Manheimer said that Gee had had previous contact with the victim, 24-year-old Loan Kim Nguyen. Gee had stalked Nguyen for a period of several weeks, pursuing her via messages on the internet before laying in wait and making entry into Nguyen's home through the garage Tuesday morning.

"The suspect surreptitiously entered the victim's home as the husband was leaving for work. We have evidence the suspect physically assaulted the victim and threatened to kill her numerous times," said Police Chief Manheimer.

Manheimer noted that Gee has a prior history of weapons possession and had been arrested for illegal possesion in a different county during the press conference. She also said that preliminary forensic evidence incidated that Nguyen had been fatally struck by bullets shot from Gee's handgun through the wall of an adjoining bedroom as she handed her young children to safety through a window to waiting SWAT team members.

Contrary to earlier reports that Gee had been killed in the ensuing gun battle with responding SWAT officers, Manheimer said preliminary forensic evidence showed that Gee died of a single self-inflicted gunshot wound to the head. Police are now investigating the incident as a murder-suicide.

A source familiar with the investigation told KTVU that Nguyen was transported to the hospital with a police handcuff on one wrist, a possible sign that Gee had tried to hold her captive.

On Tuesday, San Mateo police said they received a call from a man at about 9:40 a.m. about an armed robbery underway at a home on Hobart Avenue near South El Camino Real. The caller told police his wife and children -- aged 1 and 3 -- were in the house and had barricaded themselves in a bedroom, police Deputy Chief Mike Callagy said. The man wasn't home at the time, but had received a text message from his wife about the invader, according to officers.

Officers arrived at the scene and set up a perimeter around the house. The male suspect was observed inside the residence with a handgun, according to officers. After a shot was heard fired inside the home, a Special Weapons and Tactics team was summoned. Hostage negotiators were also brought in to attempt contact with the suspect in an effort to get him to surrender, Callagy said.

SWAT officers surrounded the house and were able to get in telephone contact with Nguyen. She reported that the suspect was trying to gain entry into the bedroom where she was barricaded with her children and that she wanted to lower the children out of the bedroom window so officers could get them to safety.

"The victim in this case is nothing short of a hero for saving the lives of her two small children from the crazed gunman," Manheimer said at a Tuesday night press conference regarding the incident.

The children were uninjured in the incident and Manheimer commended the officers "who at great risk to their own safety and also under fire" saved them.

She said one officer jumped off the top of the van holding one of the children after the suspect began shooting. She said some officers may have suffered minor injuries but nothing serious.

Police served numerous search warrants Wednesday in various locations.

In addition to the criminal investigation by the San Mateo Police Department, the department will conduct an internal investigation into the officers' actions. The District Attorney's Office will also investigate that aspect.