A man who tried unsuccessfully to buy an assault rifle pleaded not guilty Monday to charges that he stalked and threatened to kill a teenage barista when she rebuffed his advances.

Kyle Eugene Copeland, 20, is being held in the King County Jail in lieu of $50,000 bail. He was charged earlier this month with first-degree harassment and stalking.

According to court documents, the victim is a 17-year-old girl who worked at a Starbucks in the Westwood Village Shopping Center in West Seattle. Trouble began for her last November when Copeland began showing up at the coffee shop buying an unusually large amount of coffee -- as many as 10 or more cups a day.

Soon, prosecutors say, he asked the girl to marry him and have his babies. She reported the odd behavior to security officers, who kicked Copeland off the grounds when he reportedly began harassing other employees in late November. Witnesses said that Copeland was belligerent with security officers.

Then, on Dec. 11 and again on Dec. 12, Copeland went to a sporting goods store in the same complex and tried to buy an SKS semi-automatic rifle with a bayonet attachment. But the store manager, knowing of Copeland's behavior, refused to sell the weapon.

Two days later, Copeland allegedly called the victim on her cell phone, threatening to kill her and her brother. He made more threats earlier this month when he saw her driving by in West Seattle.

After the teenager filed a report with police, officers went to Copeland's home to contact him. A fight broke out between officers and members of Copeland's family. Police ended up arresting some of his relatives for obstruction.

Copeland's criminal record includes convictions for auto theft, property destruction and theft. In July 2006, he stole several items, including a gas mask and other protective gear, right out of a police car after officers responded to a call in West Seattle.