CONCORD, N.H. — A man used death threats, a stun gun, zip ties and a shock collar to control a teenage girl he's accused of kidnapping at gunpoint, imprisoning and sexually assaulting over nine months, according to indictments released Wednesday.

Nathaniel Kibby was arrested in July and initially charged with kidnapping the girl Oct. 9, 2013, in the White Mountains town of Conway. Despite a massive search and widespread public outreach, there was no trace of her except for a letter she wrote to her mother that November.

The girl, who turned 15 a week after she disappeared, returned just as mysteriously in July, a week before Kibby was arrested.

Media outlets, including The Associated Press, repeatedly published the girl's name and picture after she disappeared and when she returned home. The girl's family and prosecutors have asked that her name and image no longer be published because they fear the publicity and association with sexual abuse will slow her recovery.

Kibby, 34, was indicted in two counties this week on charges including kidnapping, sexual assault, robbery, criminal threatening, illegal use of a gun and illegal use of an electronic restraint device. More than 150 of the indictments were heavily blacked-out. The charges carry penalties that could effectively send Kibby to prison for life if convicted.

Public defender Jesse Friedman said Kibby maintains his innocence. Friedman notes the charges are only allegations.

According to the indictments, Kibby threatened to kill the girl, her family and her pets and used a "taser-like" device to punish her when she "carved" information about his identity in a letter to her mother. Prosecutors say he forced her to lie in that letter and made her rewrite it. As he began to fear an investigation, Kibby put a gun in her hand and told her it would be better to shoot him than give authorities any information, according to the indictments. He also forced her to wipe down the surfaces of a shipping container outside his trailer to remove her fingerprints and to pour cleaning fluid into plumbing drains to remove hair or DNA evidence, the indictments say.

Kibby also is accused of falsifying evidence by destroying or removing gags, anti-barking dog collars, a fake surveillance camera and an aquarium pump with tubing that had been used to provide the girl with water when she was restrained on a bed.

The charges say Kibby gagged the girl, put a shirt over her head and face, then put a motorcycle helmet over that. During her confinement, he used the stun gun to control her, made her wear a shock collar, bound her wrists with zip ties and taped her eyes shut, the indictment said.

Kibby told the girl he would only release her if she lied to police about what had happened and what he looked like, the indictments say.

Kibby has been held on $1 million bail since his arrest at his home in Gorham, about 30 miles from the girl's home. He has a criminal history dating to 1998, including convictions on simple assault, criminal trespass and breach of bail conditions.

At an afternoon press conference, Attorney General Joseph Foster said his office doesn't usually address the media after indictments but added, "There are unique aspects about this particular case and the victim that warrant it."

Lyn Schollett, the executive director of the New Hampshire Coalition Against Domestic and Sexual Violence, said the girl "continues to heal and to thrive now that she is reunited with her family."

Kibby is to be arraigned Jan. 8-9 in each of the counties where he was charged.

Police said the girl, now 16, was last seen after leaving Kennett High School in Conway. She walked her normal route down a busy road toward home and sent several texts to a friend. But when her mother returned from work, the girl wasn't home. Prosecutors said she "went dark" and could not be traced through social media for the duration of her absence.

Kibby grew up and attended school in Conway, a tourist-dependent town of about 1,800 people in the southeast corner of the White Mountain National Forest. He worked as a machinist at two gun makers.