By Yereth Rosen

ANCHORAGE, Alaska (Reuters) - An Anchorage construction contractor was indicted on Wednesday on charges of kidnapping a teenage barista from a drive-up Alaska coffee stand, killing her, and extracting ransom payments from her family after she was already dead.

Israel Keyes, 34, was accused of murdering 18-year-old Samantha Koenig, whose body was found in early April in an ice-covered lake just outside of Anchorage two months after she was snatched from the coffee stand at the end of her shift.

The case has gripped residents of Alaska's largest city, who put up posters of the missing woman, contributed to a reward fund, held candlelight vigils and provided self-defense training for other baristas.

Keyes, who prosecutors say has no previous ties to Koenig or her family, has been in custody since he was arrested last month in Texas and identified as a "person of interest" in the case.

He was charged on March 27 with fraudulent use of another person's credit-union debit card.

The federal kidnapping and murder charges in the new indictment carry maximum penalties of life in prison or death, Assistant U.S. Attorney Kevin Feldis told a news conference.

According to the indictment, Keyes forced Koenig from her coffee stand and into his pickup truck, confined her and killed her early the next morning.

Before killing her, he stole a debit card from a vehicle near Koenig's home and got her to give him the card's personal identification number, the indictment said.

Keyes, about three weeks after Koenig was killed but before her body was found, sent a text message on her cell phone demanding a ransom payment into the credit-union account connected to the debit card he took, according to the charges.

Koenig's family used the reward fund to make the deposit, and law-enforcement agents tracked Keyes through automatic-teller withdrawals made in Alaska, New Mexico, Arizona and Texas, Feldis said.

Keyes was a former U.S. Army soldier who moved to Alaska in 2007 from Washington state, according to his company's website.

(Editing by Dan Whitcomb, Cynthia Johnston and Lisa Shumaker)