Figures released by the Crime Statistics Agency on Thursday show the 10 to 24-year-old cohort allegedly committed 640 offences in Warrnambool in the year to March 2019 - a 13 per cent jump from the previous year and the highest it has been in a decade.

Of those offences, 62 per cent were allegedly committed by youth aged between 18 and 24.

Almost half the crimes were property and deception-related offences, which include burglaries, theft, deception, property damage and bribery.

And 27 per cent were crimes against the person such as assaults, robbery or stalking, harassment and threatening behavior.

Last week a 15-year-old Warrnambool youth appeared in Warrnambool Magistrates Court after taking LSD, jumping on a car and spitting at police officers. His case was adjourned so he could pay for the damage he caused.

And in April a 21-year-old man on bail was charged with stealing more than $60,000 worth of goods, including several quad bikes, from properties in Werneth, Jancourt East, Simpson and Scotts Creek.

Victoria Police western region division two Inspector Paul Marshall said the increase in youth crime was particularly concerning.

He said one contributing factor was the identification of criminal activity through the family violence investigation unit and Risk Assessment and Management Panels (RAMPS), which is a formally convened meeting held at a local level with key agencies and organisations.

"We know we are having problems with our young people, especially with our 10 to 15-year-old's who are getting involved with domestic situations with their parents or other family members," Inspector Marshall said.

"But through community confidence, and victims knowing that we are actually going to do something to support them, they are reporting it to us. That is pushing up the rate of family violence incidents, youth crime and assault-related incidents.

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"It also sees the rate of property damage soar. Ordinarily a fist through the wall at a family home would not be reported but we are at a stage where it is being reported and that is great because it means we are getting to intervene after the first incident, rather than the 20^th incident. That way we can provide referrals and get support agencies on board."

Inspector Marshall said police youth resource officers were working very closely with local schools to combat the increase in youth offending and identify more offenders.

"The figures show that young people, particularly that 18 to 24-year-old cohort, are committing more offences. Why are they doing that? I wish I knew the answer," he said.

"Every time we process a young offender we want to vigorously try to understand their motivation and their why. We are also working very closely with our local schools to try and identify those reasons and prevent crime from occurring."

Inspector Marshall said the 18-24-year-old cohort often became involved in criminal activity after using drugs.

"The more drugs that are in the town, the more offending we see," he said.

"Unfortunately we are living in a time where ice is the drug of choice. Traditionally, people were using things like heroin and cannabis that were a bit of a downer. But now they're using methamphetamine and fentanyl, which are more psychotic drugs that produce longer episodes of heightened, drug-induced rage.

"They use drugs and they go on a bit of a rampage. They'll go out and damage 15 cars instead of one. They'll commit multiple crimes and there'll be multiple charges. As always, drugs is a big issue."

Inspector Marshall said police were also seeing an increase in thefts, including shop steal and petrol drive-offs.

"That sort of offending is most common in those aged between 20 and 25," he said.

"Traditionally, operators might not have reported petrol thefts to us but we have targeted this type of offending by going to those operators and saying 'we want to know these things'. Often the people committing those gateway offences are committing more serious offences and if we can nail them on anything, we are happy with that.

"It also provides us an opportunity to intervene with their offending and hopefully change their direction."

The city's youth crime rate remains significantly lower than other major regional cities such as Ballarat, Bendigo and Geelong but higher than Horsham.

In the Southern Grampians, youth crime rose by 43 per cent from the previous year and 25 per cent since 2010.

The 18 to 24-year-old cohort made up nearly 74 per cent of that offending, with mostly driving, transport and other government regulatory offences.

Moyne and Glenelg experienced their lowest youth crime rate in a decade, while Colac-Otway saw a slight rise (five per cent) from the previous year but a 49 per cent drop from 10 years ago.

In Glenelg, the number of assault-related offences committed by 18 to 24-year-old's dropped by 61 per cent, while property damage fell 69 per cent.

Colac-Otway youths aged between 10 and 17 committed double the amount of thefts than their older cohort, but less assault-related offences.

In Corangamite, youth crime dropped by 50 per cent in the last decade and 30 per cent from the previous year.

The CSA data revealed overall crime in Warrnambool was also the highest in 10 years, with 11,521 offences per 100,000 population recorded in the year to March 2019, up 12 per cent from the year before.

READ more: Offending in Warrnambool hits 10-year high

Theft offences rose by 26 per cent, assaults were up nearly 10 per cent, burglaries dropped by 11 per cent and drug-related offences were down 10 per cent.

Meanwhile, the number of justice procedures offences, including breaches of orders, jumped 32 per cent - the highest it has been in a decade. Inspector Marshall said he was comfortable with the steep increase.

"There is a really steep increase across there that we are OK with it because we know what is driving it," he said.

"We have been running our specialised family investigation unit for about 18 months now and what they have been doing is going and cold casing every single job they get. Every single victim or incident that they manage, they will go back through the history of the offender and sit down with victim and talk with them at length over coffee to get a very detailed version of events.

"That will resort in someone being charged with not just one singular incident. By going back and cold casing they might end up coming out with 17 charges, which drives that increase in crime."

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