A Houston woman who appeared in erotic videos torturing and killing puppies is the first person prosecuted under a federal law prohibiting so-called "crush" videos.

Ashley Nicole Richards, 25, pleaded guilty last year and was sentenced to 10 years on state charges.

Richards also became the first person charged under the Animal Crush Video Prohibition Act of 2010 and agreed to testify against Brent Wayne Justice, who produced and sold the obscene videos.

Justice, 55, is serving a 50-year prison sentence for his crimes. He was also sentenced last month to nearly five years under the federal law.

Prosecutors say the two used meat cleavers and other knives to torture the pets. Richards appeared in most of the videos, in which she was scantily clad and often wearing a Mardi Gras-style mask and "engaged in sexually charged dialogue meant to arouse the viewer."

Brent Justice produced the obscene videos, and Ashley Richards appeared in them.

One video shows her cutting on a pit bull puppy before severing its head.

"I knew what crush videos were," said Houston police Officer Suzanne Hollifield, who originally investigated the case after a tip from PETA. "I had been trained to recognize them, but I never expected to see something like that in my career."

Houston police sought help from the FBI, whose agents followed the videos' "digital breadcrumbs" to clients across the U.S. and as far away as Pakistan and Italy.

"It is very cruel video with lots of action and sexy scenes you will like," read one e-mail sent to a client. "Let me know if you like it and what you can afford."

Special Agent David Ko said he had to review 16 hours of video to get ready for the initial grand jury indictments in 2012.

"It's extremely violent. It's tough to watch," Ko said in a written statement. "It's gratifying to know they're arrested, behind bars, and not doing these types of crimes anymore."