A Lakeport man charged with fatally stabbing a neighbor he apparently thought was a pedophile now faces an additional charge of sharpening a toothbrush into a weapon while incarcerated.

Ivan Garcia Oliver, 29, has been charged with a felony count of possessing a weapon in jail, said Lake County Sheriff Rod Mitchell. He already was facing a first-degree murder charge in the stabbing death of Michael Dodele, a convicted rapist, in November.

In a jailhouse interview, Oliver told the Los Angeles Times he thought Dodele was a child molester, based on a faulty reading of the charges on an official sex offender Web registry. He said he acted to protect his son.

However, Dodele's sex crime conviction was for raping an adult Santa Rosa woman. Because he was a repeat offender, Dodele served nearly 20 years for the assault before being released two months ago.

Oliver previously was convicted in San Diego County of assault with a deadly weapon for stabbing a man multiple times, said San Diego County District Attorney's Office spokesman Steve Walker. In that 2003 case, Oliver stabbed a security guard who confronted him and and two other men after they left a restaurant without paying, he said.

He was sentenced to four years in prison, Walker said.

The discovery last week of the sharpened toothbrush was particularly troubling given Oliver's record, Mitchell said.

"Based on this man's history, I certainly think the discovery may have prevented a very serious injury to someone else, particularly a member of my staff," he said.

Mitchell said Oliver cannot claim to have made the device in order to protect himself because he was being held in protective confinement away from other inmates.

"He was in no danger," Mitchell said.

A corrections officer discovered the weapon last week while searching Oliver before moving him from one solitary cell to another, Mitchell said.

You can reach Staff Writer Glenda Anderson at 462-6473 or glenda.anderson@pressdemocrat.com.