Lance Cook, 32, from Shepparton, appeared in Shepparton Magistrates’ Court via video link on Tuesday over the incident which the court heard left staff feeling “threatened” and “shaken”.
Police lawyer John McNamara told the court the accused attended the store on Wyndham St on March 13 this year where he approached the front counter and asked to return a phone.
After being advised that he could not return the phone because the screen was damaged, the accused became "aggressive" and stated if the store did not accept the item he would get his gun and "hold up this place".
“The witness felt threatened and pressed the hold-up alarm and informed the accused the police had been notified,” Mr McNamara said.
The accused returned to the store about 30 minutes later carrying a glass bottle of Jim Beam in a brown paper bag.
After asking staff once again if he could return the mobile phone, Cook asked if they wanted him to "come back and shoot you all up".
The accused was later arrested, charged and bailed over the incident.
“The accused made no admissions. The interview ended prematurely due to the erratic behaviour of the accused,” Mr McNamara said.
The court heard Cook was also involved in an incident on June 11 which saw him pick up a garbage bin and throw it through the front window of a Shepparton home.
“The complainant and her one-month-old daughter were inside at the time, the baby daughter was situated near the window,” Mr McNamara said.
Cook was later arrested and interviewed where he "denied all allegations" put to him.
The court heard Cook later pleaded guilty to the charges stemming from both incidents.
Cook's lawyer Laurence Waugh urged Magistrate Peter Mithen to consider deferring his client's sentence to give him an opportunity to "show that rehabilitation had taken place".
Mr Waugh said his client's diagnosis of intellectual disability and schizophrenia meant he could not "appreciate the wrongfulness" of his actions.
“If my client is to be a functioning member of society he has to come to appreciate this behaviour can't be accepted ... he is also a very vulnerable person,” Mr Waugh said.
The court heard ice, cannabis and alcohol may have been contributing factors for Cook.
Mr Waugh argued a deferred sentence would allow his client to develop a relationship with medical professionals to ensure he received the "best possible care".
“This would allow the court to be fully informed ... hopefully the groundwork can be put in place to start proper relationships with treating doctors,” he said.
Mr Mithen acknowledged the very serious nature of the allegations and the fear placed on the victims.
“When that bin went through the window (the victim) was minding her one-month-old baby — that would have scared the daylights out of her,” he said.
Mr Mithen adjourned the matter for one month.
“The idea is that you commit no further offences and you abide by the directions of the people in your life trying to help you,” he said.