An accused killer convicted in April of a sex crime involving a juvenile learned Wednesday that East Baton Rouge Parish prosecutors are seeking to have him sentenced as a habitual offender.

If prosecutors are successful in having Percy Cage classified as a fourth-felony offender, the 41-year-old Baton Rouge man would face a potential sentencing range of 20 years to life in prison.

“All of it is a major problem. It’s the domino theory,’’ Cage’s attorney, Robert Tucker, said after court of the significance of what prosecutors are trying to accomplish.

Under the state’s habitual offender law, classification as a fourth-felony offender carries the highest potential sentencing range.

State District Judge Tony Marabella on Wednesday scheduled a habitual offender hearing in Cage’s case for Nov. 3.

Cage is awaiting trial on second-degree murder, second-degree feticide and other charges in the Aug. 14, 2009, shooting deaths of a pregnant woman and her teenage brother.

He was indicted on those charges in October 2009.

An East Baton Rouge Parish jury found Cage guilty April 5 of carnal knowledge of a juvenile. He was accused of having sex with a girl between February 2006 and January 2008 when she was under the age of 17.

Carnal knowledge of a juvenile carries up to 10 years in prison.

Cage pleaded not guilty Wednesday to a habitual offender bill of information filed by prosecutors Friday.

“The State seeks to enhance Defendant’s sentence for his conviction of Carnal Knowledge of a Juvenile,’’ prosecutor Darwin Miller says in documents attached to the bill of information.

The documents state that Cage:

• Pleaded guilty April 4, 1990, to simple burglary of an inhabited dwelling and was sentenced to six years in prison.

• Was convicted April 10, 1995, of first-degree robbery and was sentenced to five years in prison.

• Pleaded guilty to July 13, 2000, to illegal possession of stolen things and was sentenced to four years in prison.

Miller noted in the documents that Cage pleaded guilty to additional charges on April 4, 1990, and April 10, 1995. He also pleaded guilty May 9, 1991, to felony theft and simple escape, the documents state.

In the August 2009 incident, Cage is charged with two counts of second-degree murder in the slaying of Tanya Smith, 31, and Renea Boreaux, 15, and one count of second-degree feticide in the death of Smith’s unborn child.

Smith was eight months pregnant, according to police. Cage was an ex-boyfriend of Smith, police said. The shootings occurred while Smith and her brother slept in their Syble Drive home, police stated.

Cage also faces charges of attempted second-degree murder and aggravated criminal damage to property.

He is accused in the beating and shooting of a former girlfriend in January 2008. The woman was shot in the chest but survived.

East Baton Rouge Parish District Attorney Hillar Moore III has described Cage as a “menace.’’