CHANDLER, Ariz. – An 18-year-old high school student caught with his 48-year-old math teacher in her bedroom was stabbed to death by her boyfriend, who was himself a former student of hers, police said Tuesday.

Chandler police said 20-year-old Sixto Balbuena told them he never meant to kill Samuel Valdivia. He allegedly told police “the blade went in like going into butter” and that he just wanted to show Valdivia how much he hurt him by sleeping with Tamara Hofmann.

Sixto Balbueao, 20, was charged with second-degree murder after he allegedly stabbed his 48-year-old girlfriend’s teenage lover.
Balbuena, a Navy sailor on leave from California, was arrested on a charge of second-degree murder after police found him covered in blood and told them about the killing. He remained jailed in lieu of $100,000 bond on Tuesday and did not yet have a lawyer.

Balbuena found his girlfriend naked and Valdivia in his boxer shorts in the woman’s bedroom around 2:40 a.m. Friday, according to police reports and court documents.

Balbuena told police that Valdivia apologized to him before Balbuena began kicking, punching and throwing things at him, according to a police probable cause statement.

Police said Balbuena told them he “wanted to teach the victim a lesson,” and stabbed him in the lower side with a kitchen knife, according to the court document. Valdivia later died at a hospital.

He also threw Hofmann to the floor jumped on top of her and demanded to know how long she had been cheating on him, according to the document.

Police said Hofmann taught Valdivia math at El Dorado High School in Chandler and was also Balbuena’s teacher when he attended Marcos de Niza High School in Tempe.

A call to both schools was not immediately returned Tuesday. Hofmann’s phone number is unlisted.

Balbuena is the one who called 911. He told officers he felt remorse for stabbing Valdivia after seeing him lying on the floor struggling to breathe, police said.

Police spokesman Sgt. Joe Favazzo said Hofmann is being investigated for potential misconduct relative to her involvement with Valdivia.

A 2006 Chandler police report obtained by The Associated Press on Tuesday shows that police suspected Hofmann of having a sexual relationship with a then-17-year-old Balbuena.

Both Hofmann and Balbuena denied being in a sexual relationship, and police closed the case.

From the East Valley Tribune:

School officials knew that the 48-year-old teacher in a deadly love triangle with a student and former student had been in a questionable situation with the slaying suspect when he was 17.

Teen stabbed in Chandler home

Math teacher Tamara Hofmann had been disciplined and eventually resigned from Marcos de Niza High School after Chandler police found her parked at 1 a.m. in 2006 with student Sixto Balbuena, now 20, who had her bra in his pocket, according to school records.

Hofmann then went on to teach at El Dorado High School, a Chandler charter school for at-risk students, where she met Samuel Valdivia, an 18-year-old student who police say was slain by Balbuena Friday when he caught the two in bed.

The State Board of Education has known since March 2007 about her record with Marcos de Niza and began its own investigation that could have led to Hofmann losing her teaching certificate, but the investigation was put on hold because of Balbuena’s lack of cooperation and the lack of manpower, said Vince Yanez, executive director for the State Board of Education.

“It was not given top priority,” Yanez said.

Yanez said there is no mechanism in place for the state to temporarily suspend a teacher’s certification while they are under investigation.

Decertifying someone requires a full due process, which includes the investigation, the filing of a complaint, the teacher’s written response, an administrative hearing and possible appeals, Yanez said.

He added, however, that all public and charter schools, including El Dorado High School, have access to a secure state Web site that shows all of the teachers who are under investigation.

El Dorado High School did not respond to repeated calls seeking comment.

On Monday, however, principal Ramona Gonzalez said Hofmann has been suspended from the school since the Friday incident.
Sixto Balbuena

Hofmann, who earned a master’s degree in 2003 from ASU with a 4.0 GPA, taught in the Kyrene School District for 10 years before landing a job at Marcos de Niza in 2005. Her resume includes a long list of committees she joined and leadership roles she has taken over the years.

According to a Chandler police report from Nov. 1, 2006, Hofmann and Balbuena were parked in a car on a dark street far from their respective homes when neighbors became suspicious and called police.

Hofmann told police she stopped to empty a leaky ice chest. She also said Balbuena was a family friend and he had her bra because she had changed clothes earlier in the car by herself and later asked him to throw the clothes in the back.

“Hofmann said she did not know Sixto had taken her bra,” the report states.

Balbuena said his parents knew he was with Hofmann, but when the officer checked, the parents said they didn’t know, and they alerted the officer that she was his math teacher.

The officer questioned them about whether they had sex, but the officer couldn’t establish any proof, so he wrote a report and forwarded it to the Tempe Union High School District, which took her out of the Marcos de Niza classroom the next day.

In all, she was docked 10 days’ pay, reassigned to work in the district’s administrative offices and resigned on May 25, 2007.

Her personnel file also shows that she had been alone in her car with Balbuena on other occasions and been ordered by the principal to stop.

Assistant superintendent Janet Seegren wrote in Hofmann’s disciplinary file that she was troubled the teacher found “sufficient reasons for such behavior; i.e., he is not ‘your student,’ he is ‘family’ to you.”

Court records show Hofmann has been going through a contentious divorce since December 2007.

She did not return a call or e-mail seeking comment.

Valdivia’s mother, Placida Maldonado, and brother, Jose Valdivia, said Hofmann called Samuel Valdivia at 11:45 p.m. Thursday and asked him to come over.

Family members said they don’t believe he was dating Hofmann and that the night he died was the first time they know of that he had seen her outside of school.

According to court documents, Balbuena was on leave from the Navy when he arrived at Hofmann’s home in the 2500 block of West Ironwood Drive about 2 a.m. and called her to let her know he was outside.

There was no answer so Balbuena let himself in, heard noises from the bedroom and thought something was wrong.

He grabbed a knife from the kitchen and entered the bedroom, where he saw a man run into the bathroom.
Tamara Hofmann

Balbuena forced his way into the bathroom to find the man in his boxer shorts and Hofmann nude.

He began beating the man and throwing things at him, including a computer printer.

Balbuena told police he didn’t want to kill the man when he stabbed him, just inflict pain.

“He said that he stuck the knife in too far, stating the blade went in like going into butter,” the court document states.

Balbuena then attacked Hofmann but did not stab her.

Balbuena, who was covered in Valdivia’s blood, called 911 to get the man help and waited for police to arrive.

Balbuena is in jail in lieu of $100,000 bail.

“He was a good boy, a very good boy,” an emotional Maldonado said of her son, who aspired to be a singer. “This morning I was so angry. Maybe if my son was a pothead or a gangbanger I would’ve expected something like this, but I can’t accept it.”

She and the other family members reminisced on Tuesday about “the baby of the family” of six siblings (five sons and one daughter).

He loved music and sports and played baseball for the El Dorado High School team.

A memorial to Samuel adorned with flowers, family pictures and a framed LeBron James Cleveland Cavaliers NBA jersey served as a reminder at the family’s home, where many of his nieces and nephews ate hot dogs at a picnic table in the driveway in the shade of bougainvillea bushes.

Speaking through a translator, Jennifer Soto, 15, a friend of Samuel’s, Maldonado said she wanted those responsible for her son’s death to pay and wants to get the word out to keep something like this from happening again.

Jose Valdivia said he raised his brother since he was 10 and sometimes went fishing with him and played soccer with him.

“I wanted him to grow up like normal people,” he said.