Discuss as:

Navy veteran accused of injecting 2 Alaska teens with heroin

Anchorage Police Dept. via AP

Sean Warner, 26, is accused of charges including manslaughter. According to his family, Warner served as a Navy field medic in Afghanistan and now suffers from post-traumatic stress.

ANCHORAGE - A 26-year-old Navy veteran who served as a medic in Afghanistan pleaded not guilty Thursday to charges he injected two Alaska teens with drugs on separate occasions, giving one of them a fatal dose.

Sean Warner was first charged with injecting Jena Dolstad, a 14-year-old from Anchorage. She died from the heroin dose almost a week later, and the charge was consequently raised to manslaughter.

He is also charged with evidence tampering and two counts of misconduct involving a controlled substance.

Court records show Warner now faces a new charge of earlier injecting another teen with heroin sometime between Dec. 14 and Dec. 21.

Police Lt. Dave Parker said the second teen — identified only as "R.H." — is a 17-year-old girl. He said she was injected multiple times by Warner.

Anchorage authorities believe Warner didn't intend to harm the girls.

Warner is being held on $100,000 cash bail. A trial was set for March 27.

Dolstad's stepfather, Brett Williams, told NBC station Channel 2 news/KTUU.com his family had some ups and downs, but Jena always came back home. Williams said he's now making arrangements for her funeral and celebration of life.

He told the station she was a typical teenager. He said her mother wasn't around much, and added Jena, simply, made a wrong choice.

“I know she got mixed in with some people I tried to warn her about,” he said on the phone. “And it went from there.”

'She just made a mistake'
A single father who works graveyard shifts, Williams insisted he gave her a stable home.

When asked if his stepdaughter slipped through the cracks, Williams responded, “She just made a mistake, that’s all she did.

A number of Facebook tribute pages have been set up in honor of Dolstad.

Warner's uncle, Doug Tweedie of Bend, Ore., told The Associated Press that Warner served as a Navy field medic in Afghanistan and now suffers from post-traumatic stress.

Tweedie said he and his wife helped raise Warner and that Warner did very well in school and was ambitious. Warner also did well in the Navy, he said.

Tweedie said he spoke with Warner through Warner's father.

"He's terribly remorseful," Tweedie said Thursday. "He's in a very difficult spot."

According to court papers filed before Dolstad's death, two other men went with Warner to pick up the girl the evening of Dec. 22, and they took her to Warner's home to hang out.

Warner was sharing a gram of heroin with the men, and Dolstad said she was willing to try something "new" but didn't want to inject herself, according to the court papers. Warner tried to inject the girl but failed, so he had her lie on his bed and hold out an arm. He then used his belt as a tourniquet and shot 25 to 30 units of heroin, taking several times to find a vein, the papers say.

The two witnesses told authorities they left the girl — identified as "J.D." in court papers — on the bed and found her the next morning, face-down in her vomit.

Warner initially balked at calling 911 because he feared authorities would find drugs, and instead gave the teen Suboxone, a prescription drug used to treat opiate addicts, the court papers say. He called 911 after the girl began to convulse a couple of hours after he gave her the Suboxone, the papers say.

Warner locked his bedroom door, and responding officers didn't search it when he told them it was his roommate's room, according to the documents. After police left, Warner and one of the witnesses put needles and other "related evidence" into a box then tossed it behind a trash bin at a nearby business, according to the papers, which say police later recovered paraphernalia including syringes.

Dolstad was found to have heroin, methamphetamine and cocaine in her system when she was brought to the hospital, charging documents said. Medics told authorities she sustained damage to her brain and heart.

Authorities have said the heroin used is known on the street at "China White," considered more potent than common tar heroin.

As far as Tweedie is concerned, no one really knows what happened.

"At this point, two addicts are blaming another addict," he said. "I don't know if I believe another addict."

Figures published last month by the University of Michigan's Monitoring the Future program — an ongoing study of the behaviors, attitudes, and values of American secondary school students, college students, and young adults — show the level of heroin use had remains "steady" but marijuana use has risen for four straight years.

Alcohol use — and occasions of heavy drinking — continued a long-term gradual decline among teens, reaching historically low levels in 2011, the study found.

More content from msnbc.com and NBC News:

NBC News, The Associated Press and msnbc.com editor Alastair Jamieson contributed to this report.