A 29-year-old man has been sentenced to more than a year in prison for posing as a U.S. Marine and cyberstalking and threatening women on online dating sites across Virginia and the mid-Atlantic region.

James M. Johnson, of Roxboro, N.C., pleaded guilty in federal court in Alexandria to one count of cyberstalking and one count of making interstate threats. He was sentenced Friday to 15 months in prison.

Prosecutors say Johnson, who used the screen name "Cuddleman," created an online dating profile posing as "Shawn Davis," a U.S. Marine purportedly stationed at Quantico or off fighting in Iraq.

Johnson was not a Marine and had no affiliation with Quantico, federal prosecutors said.

Johnson concocted a false backstory on Davis' family and military experience that was believable enough to fool women who grew up in military families.

He used information belonging to an actual Marine with the same name but a different set of photos showing "Shawn Davis" in military uniform, holding guns or with a new pickup truck. Johnson told investigators that he does not recall where he obtained the photos.

Prosecutors say Johnson expressed having a romantic interest in his victims to coerce them to send him nude pictures or perform sex acts in front of a video camera.

When the women refused, Johnson threatened to rape them, kill them or their children or post altered images of the women performing sex with animals on pornographic Internet websites, court documents said.

Johnson admitted to threatening 11 women between July 2009 and October 2010.

For instance, in 2009, when one woman refused to purchase a camera for her computer, Johnson responded:

"[Expletive] get a cam so I can see you or your [sic] dead. I am not playing. I will do everything to kill you," Johnson wrote, according to prosecutors.

In another instance, Johnson told a victim he would "slit [her] throat and send his friends to kill [her]."

Johnson was able to determine where the women lived, even though they had not told him, and he "used this skill to frighten several victims," according to court documents.

The women fled their houses, had friends stay over for protection or asked police to monitor their houses, documents said.

In September 2010, Johnson repeatedly harassed a woman in western Pennsylvania. When a police officer answered the woman's phone, Johnson threatened to "blow up" the woman's house if the police did not leave.