NEWPORT BEACH — A 32-year-old man with previous felony convictions accused of threatening a mass shooting at UC Irvine was convicted Wednesday of multiple weapons violations.

Sebastian Bogdan Dumbrava was convicted of five counts of manufacture, sale, or receipt of a large-capacity magazine that is prohibited, all felonies. Jurors deadlocked on felony counts of delivery of a threatening letter with intent to extort and attempt to extort property or other consideration by means of threat.

Dumbrava was scheduled to be sentenced Jan. 6. A pretrial hearing is also scheduled for consideration of the charges jurors deadlocked on.

Dumbrava was convicted in March 2021 of unlawful possession of a firearm and being a prohibited person owning ammunition, both felonies.

Dumbrava made threats on Twitter and sent emails to UCI officials throughout 2019 and the beginning of 2020, according to an affidavit from UC Irvine police detective Samuel Soon. The threats “referenced firearms, the Virginia Tech school shooting, the Virginia Tech active shooter and his self-identified six stressors that are common in active shooters,” Soon said.

Dumbrava also “made a comment about the possibility to acquire a firearm that can be used to indiscriminately massacre students,” Soon said.

Dumbrava was arrested Jan. 10, 2020, and convicted March 16, 2020, of unlawful possession of a firearm and a prohibited person owning ammunition, both felonies. He was sentenced March 24, 2021, to three years and eight months in state prison, according to court records.

After he got out of custody, from October through December 2021, Dumbrava tweeted that “Judge (Scott) Steiner stated that he believes I will commit a mass shooting at UC Irvine sometime next year in 2022,” Soon said in the affidavit. “He also apologized to the UC Irvine students that he believes I will massacre, stating he is sorry that he cannot do more to prevent me from killing them.”

Dumbrava also allegedly tweeted on Oct. 25, 2021, “In the year 2020, I had prepared to commit a mass shooting on the UC Irvine campus,” Soon said. “My intent was to cause financial injury to the university. I had planned to pursue the shooting of students in the event that the university failed to provide restitution for my injuries.”

Dumbrava was arrested Jan. 11, 2022, for violating terms of his probation and investigators found receipts from guns tores in Arizona that were stored in his mother’s storage locker in Anaheim, Soon said.

After a flash incarceration, Dumbrava was released Feb. 23, 2022, and ordered to report to his probation officer, but failed to do so, Soon said. That prompted an arrest warrant for Dumbrava, who had been living out of his mother’s car, Soon said.

Dumbrava called his mother on Feb. 28, 2022, from a phone that blocked caller ID who “begged” him to turn himself in to authorities, Soon said.

Dumbrava was arrested by Garden Grove police on March 5, 2022, and sentenced to 90 days in jail for the probation violation, Soon said.

“He is a highly educated individual with an advanced comprehension of technology,” Soon said.