She also is accused of seriously injured another child, Diana Romero, 9, at her home, according to Gwinnett Daily Post.
CBS46 reported that the judge ordered Martinez to stop playing to the cameras during the odd court appearance. "Alright?" But the judge tried to have Martinez reconsider her decision to not have an attorney representing her, ".and I doubt that you are well equipped to handle that on your own, but that's your decision.
"Right now we believe we have everybody involved in this crime", Cpl Pihera said.
Martinez is being held at Gwinnett County Jail on five counts of murder, five counts of malice murder and six counts of aggravated assault. When officers got to the scene, a grisly scene awaited them: the bodies of four children and their father, allegedly stabbed to death by their mother.
She reportedly told the judge that the people and her faith would act as her attorney, ABC News reports.
Her behavior in court was freakish and erratic as she smiled to the media and gave two thumbs-up to the cameras.
U.S. Customs and Immigration Enforcement spokesman Bryan Cox said in an email Friday that Maria Isabel Garduno-Martinez, whom local law enforcement identified as Isabel Martinez, is from Mexico and entered the U.S. illegally. Police believe Martinez made that call.
Other cases get less attention, as when a woman kills a newborn or in children's deaths blamed on neglect, said Cheryl Meyer, a psychology professor at Wright State University in OH and co-author of two books on mothers who have killed children based on about 1,000 cases during the 1990s.
Martinez was immediately taken into custody and a Gwinnett Police Department spokeswoman said the mother was cooperating with police, although a motive for the alleged killings is unclear.
The judge gave her a warning as he was reading her charges.
Police said a fifth child, a girl, survived with serious injuries.
Thorpe advised Martinez to hire a lawyer or allow one to be appointed. Another child was hospitalized and is now in serious but stable condition. The children who are deceased were aged 2 to 10.
"This is a horrendous crime, not only for the victims but for the extended family, neighborhood and community", police said in a statement.
Their slain father was Martin Romero, 33, Pihera said.