When did Tucson resident Moses Antonio Shepard's chasing of a woman turn into an interstate stalking case?

According to the federal government, some point before the 18-year mark.

Shepard was sentenced yesterday to 100 months in prison, as the 19th anniversary of his one and only date with his victim comes in September.

According to federal court documents, Shepard followed the woman back-and-forth across the country since getting rejected for a second date in New York in the early '90s.

While in New York, he'd call her late at night and hang up the phone. He'd go to where she worked, went to school, got on the subway, and where she lived. He mailed her a photocopy of her high school yearbook photo. Once, the woman answered the door to her apartment, and Shepard grabbed her arm to try to get inside -- which he didn't manage to do.

In 1994, the woman moved to New Mexico, where Shepard kept sending her creepy letters. One was postmarked from Phoenix, with Shepard saying he was getting closer to her.

The woman moved into a house with her parents in Tucson in 1995, where, sure enough, Shepard used his creeper skills to get her address and send her letters, and the victim got a restraining order.

In September 1996, she moved to San Diego, but kept everything registered to the Tucson address, and Shepard resumed sending letters to her parents' house after the restraining order expired.

In 2001, though, the woman's sister-in-law -- who had the same name -- underwent a rare heart surgery, and her name was published in a medical journal. Of course, Shepard sent a letter to her using the journal as a middleman.

The letters kept coming, until Shepard shifted more toward telephone calls to harass the woman.

A few years later, Shepard discovered email, and you can imagine how that went.

After one email compared himself to a guy who went on a shooting spree in a fitness center, West Hartford, Connecticut police decided that was enough, and applied for an arrest warrant for Shepard -- for the fifth time.

Since Shepard was living in Tucson at the time, the feds got involved, arresting him and hitting him with a pair of interstate-stalking charges.

The FBI says that in sentencing Shepard to 100 months in prison, "Judge Jorgenson noted the extreme distress caused to the victim and Shepard's lack of remorse for his crimes."

At least the woman has an eight-year head start to get way, way the hell away from Shepard.