Johanna Orozco was only 18 when her high school sweetheart, Juan Ruiz, shot her in the face.

But in many ways, that violent climax in 2007 was not as surprising as it should have been.

Along the way of their three-year relationship, there were lots of signs.

The two began dating when she was 15, and while everything was perfect at first, she said his behavior soon began to change. Looking back, Orozco, now 23, said the No. 1 thing girls need to look out for is jealousy.

“Jealousy comes from insecurity and that is where the controlling part starts,” she told teens at Decatur High School on Oct. 17. “Little things like calling you all the time, questioning your friends and having problems with your family are the beginning of everything.”

Orozco said the abuse began as jealousy and escalated into accusations of cheating, then pushing and shoving. After each outburst, Ruiz would apologize and profess his love. After each reconciliation, the abuse returned.

When she broke up with him for good, Ruiz raped her at knifepoint in her own bedroom in a twisted attempt to regain her affections. While out on house arrest for the sexual assault, he stalked her and shot her in the face with a sawed-off shotgun as she sat in her car at her grandmother’s Ohio home.

The blast blew off a major portion of her lower left jaw. Surgeons rebuilt what was left of her jaw with a piece of bone from her leg.After a six-week recovery, Orozco, who was in her senior year, finished her high school classes at home, attended prom and graduated with her class.

Orozco is newly married, and her husband is stationed at Fort Stewart in Hinesville, Ga. The Cleveland native, who has been on “Oprah” and “The View,” travels the country telling her story and warning teens about the red flags of unhealthy relationships.

Her trip to Decatur High was part of “Love Doesn’t Hurt,” a Domestic Violence Awareness Month program focusing on the growing incidence of domestic violence among teens.

She wears the scars of her attacks on her face, but her speech is clear as she retells her powerful story to the rapt audience of high schoolers. Every now and then, a gasp rippled through the auditorium of about 100 students.

The DeKalb District Attorney’s Office and the DeKalb Police Special Victims Unit co-hosted the interactive forum to educate students about mental, emotional, sexual and physical abuse in relationships.

Nicole Marchand Golden, DeKalb’s chief assistant district attorney, said that one in every three teens nationwide experiences some degree of domestic violence, and 40 percent of girls ages 14 to 17 know someone who has been a victim.

A 2009 Centers for Disease Control and Prevention survey found that in Georgia, one of six high school students suffered abuse at the hands of their partners. Between 2004 and 2011, the Georgia Fatality Review said that 54 percent of domestic violence killings in Georgia involved couples that began relationships as young adults.

Orozco’s speech followed a skit re-enacting a physically abusive relationship that was created by the drama club. In the skit, a male student marches up to his girlfriend, grabs a cell phone from her hand, and demands to know who she is talking to and why.

Senior Arkia Wynn, who played the battered girlfriend, said domestic violence is a critical issue.

“When you’re in high school, a lot of people joke about stuff like this,” she said. “It’s dangerous to joke about it because then people start to act like it’s OK. This showed students it’s never OK to joke about it.”

Orozco became the driving force behind Ohio House Bill 10, which allows teens to get protective orders in cases of domestic violence. It went into effect in June 2010.

Marrius Brown, a senior, said he knows teens who are in abusive relationships.

“There are some who talk about it and there are some who do not,” he said. “The statistics only show people who talk about it.”

Detective D.F. Poythress said everyone needs to talk about it.

“Anyone who is dealing with domestic violence does not have to deal with it alone,” Poythress said. “Awareness is key. There are resources out there to help and give support to those who need it.”

Victims of domestic violence, no matter their age, can call 911 for help.

The Decatur-based Women’s Resource Center offers support and shelter to women and children through its 24-hour hotline, 404-688-9436.

Wednesday’s program was a first at Decatur High, but given the positive reception, District Attorney Robert James now plans to make “Love Doesn’t Hurt” an annual event at other schools in the county.

Tiffany Hull, a sophomore, said the high incidence of teen domestic violence is outrageous. “The number could be lowered if everybody did their part. If we had more activities like this in school, the number of teens victims will not be as high.”