Police Arrest Man Accused of Stalking Teen 'Cow Belles' Stars Aly and AJ

The teen sister act known as Aly & AJ continued with plans to hold a concert Friday as a man accused of stalking and threatening them appeared in court.

Rex Mettler, 42, of Lancaster, obtained contact information for the acting and singing duo and made threats online, by phone and handwritten notes, police Detective Nick Snyder said. He declined to discuss the nature of the threats.

Aly & AJ were scheduled to perform Friday night in Cincinnati, 110 miles southwest of Lancaster. Snyder said he couldn't comment on whether any of the alleged threats involved the Ohio show.

• Photo Essays: Click here to see photos of Aly and AJ

The Cincinnati concert would go on as planned, said Rosemarie Moehring, spokeswoman for National City Pavilion at Riverbend.

Mettler was scheduled to appear in Fairfield County Municipal Court on Friday, a day after his arrest on a felony charge of menacing by stalking. He didn't have an attorney listed.

The charge stems from incidents that began Dec. 15, Snyder said.

"Rex displayed a pattern of activity over that time that reflected multiple attempts, if not numerous attempts, at stalking these females," he said.

The investigation began in southern California, where the sisters live. Lancaster police were contacted by the Los Angeles County Sheriff's Department, which provided assistance that led to the arrest, Snyder said.

Aly & AJ are Alyson Michalka, 19, and her sister, Amanda, 17, who toured earlier this year with fellow Disney Channel star Miley Cyrus of "Hannah Montana." The Michalkas had a top 20 album in 2007 and a top 20 single with "Potential Breakup Song" and are now on their own tour.

A Disney Channel spokeswoman didn't return messages seeking comment.