Andy Riu, who also described himself as a friend of Jiang, called him "very romantic." Both men said Jiang had been dating the woman for about a year and that he had flown to California several times to visit her.
The woman, a recent Rutgers graduate who lives in Los Angeles, was in New Jersey for a holiday visit.
"He loves his girlfriend," Huang said of Jiang, who has not commented publicly since he was arrested Friday night at his home. "He just went to say goodbye to her."
Two cars were parked in the driveway of Jiang's home on Saturday, and at least one person was seen inside the residence.
But reporters' repeated knocks on the home's front door were not answered.
Jiang, who is Chinese, is a doctoral student in a joint molecular biosciences program at Rutgers and has been in the U.S. since 2004. He faces a defiant trespassing charge and a fine of up to $500, and he's scheduled to be arraigned this coming week, but a hearing date has not yet been scheduled.
The Newark city prosecutor's office said late Saturday afternoon that they had not been notified whether Jiang had retained an attorney.
It was not known Saturday if the misdemeanor charge would affect Jiang's visa status. Kelly Nantel, a spokeswoman for U.S. Immigration and Customs Enforcement, said the agency is aware of the case, but she would not comment specifically on it.
Nantel said misdemeanor convictions generally do not effect someone's visa status, though more serious felony convictions often can result in a visa being revoked.
Authorities say that when Jiang breached security Jan. 3, it triggered the shutdown of a busy terminal that led to snarled flights worldwide.
New Jersey Sen. Frank Lautenberg, who was briefed on the arrest, said authorities found Jiang with "sheer, hard police work" but expressed anger that the man faces a charge he described as a "slap on the wrist."
Lautenberg also vowed to push for harsher penalties for this type of offense.
The breach led the Transportation Security Administration to shut down one of Newark's three terminals for six hours last Sunday, stranding thousands of passengers and contributing to long delays. The TSA worker who allegedly left his post has been on administrative leave since Tuesday.
On a surveillance video released Thursday by the TSA and the Port Authority, the guard is seen sitting at a security podium in an exit lane as passengers stream past on their way out of the terminal.
A man wearing a light-colored jacket stands inside a rope barrier, and the guard approaches the man, apparently telling him to move behind the rope.
Within a minute, the guard leaves the podium again and disappears into the crowd. A woman in a long white coat approaches the podium from inside the terminal; the man sees her and ducks under the security rope, and the two walk past, arm in arm.
The man was seen on a separate surveillance camera leaving the terminal about 20 minutes later, according to the TSA.
A bystander waiting for an arriving passenger noticed the breach and told the guard. TSA officials then discovered that security checkpoint surveillance cameras had not recorded the breach, and they were forced to consult backup security cameras operated by Continental Airlines.