TULSA, Okla. - Family friends say that two Oklahoma police officers accused of killing their daughter's boyfriend on Tuesday night were having troubled raising the 18-year-old, who they adopted at age 6, reports CBS affiliate KOTV.

Gina and husband Shannon Kepler are being held without bond for allegedly shooting 19-year-old Jeremy Lake on Tuesday. Shannon Kepler is facing a charge of first-degree murder, and his wife is facing a charge of accessory to murder after the fact.

Friends told KOTV that the Keplers could not have children and decided years ago to adopt. Their oldest daughter, Lisa, is now 18. Family friends said Lisa and her sister - who the Keplers also adopted - had been diagnosed with Reactive attachment disorder, which can cause serious behavioral issues. They said the Keplers spent thousands of dollars trying to get the girls the help they needed.

Gina and Shannon Kepler had Lisa in and out of programs, homes and therapy, according to family friends. But the girl was frequently kicked out or dismissed from the establishments.

Friends said the parents were at their wit's end last week when they dropped Lisa off at a homeless shelter in downtown Tulsa, hoping a dose of reality would get her back on track. There, the station reports she met Jeremy, who invited Lisa to live with his family nearby. The girl posted that she and Jeremy were in a relationship Tuesday on Facebook.

According to KOTV, Lisa and Jeremy were walking near his home on Tuesday when Shannon Kepler allegedly pulled up in an SUV, exchanged words with the couple and shot at them. Jeremy was killed in the incident.

"I've known him a week, less than a week," Lisa told the station. "He was everything. He gave me a place to stay, food to eat, a bed to sleep in. He meant a lot to me and dad came and took him away."

Police said Shannon left the scene and that he and his wife later turned themselves in with an attorney present. However, the station reports they did not give authorities the gun allegedly used in the crime or turn over SUV.

Lisa said her parents had never exhibited violence toward her or her sisters before, and that she is shocked by all of this. "I'm just so confused and lost. I don't know what to do," she said.