A Footscray “ice” addict who threatened to share revealing photos from a stolen computer as part of a string of offending has been sentenced to 30 months in jail.

Riley Brown must serve at least 18 months of his term after pleaded guilty to 14 charges of theft and multiple charges of burglary, handling stolen goods, deception and blackmail.

The bulk of the offences took place within a few weeks of his release from prison last May.

The County Court of Victoria heard Brown, 28, had been involved in the theft of letters, driver licences, assorted bank cards and other items from various letterboxes during a period of 10 weeks.

Judge Paul Grant said the behaviour involved serious breaches of the law.

“I have no doubt that the theft of these items would have, at the very least, caused their owners distress, inconvenience and frustration,” he said.

On June 10, Brown stole keys to an apartment in South Yarra and used them to steal a computer from a female teacher.

He used the computer to access her social media and email accounts, also discovering photographs of the victim and other personal information that he used to blackmail her.

He sent an email to the victim demanding $5000 within two hours or he would start posting pictures of her in her underwear and releasing all her information.

Judge Grant said this marked an escalation in Brown’s offending.

“The receipt of your emails was profoundly unsettling for the victim, who became extremely anxious and very upset,” he said.

The victim was unable to return to her apartment for five days because of severe anxiety and six months later was still suffering anxiety when home alone at night.

She said she felt a “real invasion” of her privacy and feared the photographs of her in her underwear might be sent to teachers and students where she worked, which would be “extremely detrimental to her career”.

In sentencing Brown, Judge Grant said his lengthy criminal history and drug dependency left him “guarded” about prospects for rehabilitation.