Baylor Maggenti (Daily Pilot / March 19, 2013)

A Costa Mesa man pleaded guilty this week to charges that he had an illegal stash of child pornography, dozens of guns and materials to make a bomb.

On Monday, an Orange County Superior Court judge sentenced Baylor Maggenti, 67, to one year in jail and three years of formal probation, but because of time served after his arrest, Maggenti has already completed the jail term.

Costa Mesa police originally arrested Maggenti in December 2012 after they received an anonymous tip that he had parts to build a pipe bomb.

Officers searched a business unit where Maggenti lived across the street from Whittier Elementary School and found gunpowder, fuse material and dozens of guns, including an AK-47 assault rifle, police said at the time.

Police received the tip about Maggenti three days after the Sandy Hook Elementary School shootings in Newtown, Conn.

Last year, the Orange County district attorney's office charged Maggenti with felony possession of child pornography after investigators found dozens of pictures of girls who appeared to be younger than 10 posing in scant clothing.

Maggenti also faced one felony count each for weapons and explosives possession, but on Monday, the judge knocked the weapons and child pornography charges down to misdemeanors before the sentencing.

Despite that, prosecutor Chris Duff said he was satisfied with the outcome.

"There was no indication that this was going to be used for anything," Duff said of the weapons and explosives.

Maggenti will also be required to register as a sex offender for the rest of his life, according to the prosecution.

A lawyer for Maggenti did not immediately return a call Tuesday.

The tipster who alerted police said Maggenti is a veteran who suffered from post-traumatic stress disorder, according to court documents.