The grandfather of one of the Malmsbury youth detention centre escapees says the teenager is a "good kid" who has been deeply traumatised by the tragic death of his mother.

The grandfather, who cannot be identified for legal reasons, spoke to Fairfax Media on Thursday, only hours after his 17-year-old grandson from St Albans was captured by police.

He said he was relieved his grandson had been taken into custody.

"When you have these kids stealing cars, they pose a huge risk to the community and themselves. He needs to be pulled up for his own sake," he said.

He urged the Andrews government to take a less punitive approach towards youth offenders like his grandson, who he said was easily led and had lost his mother in tragic circumstances. He did not elaborate on the death of the boy's mother.

"The government is now trying to convince everyone that the only way to fix this mess is to build more jails and lock everyone up. But it's not working and we're in a terrible mess," he said.

The teenager had spent 24 hours on the run, after escaping from Malmsbury following a riot involving 30 inmates.

He was apprehended in Colac, with a 16-year-old fellow escapee.

The duo was the last of 15 escapees to be rounded up.

It marked the end of a 24-hour frantic manhunt that spanned from Ballarat to Moe.

The youths escaped from the Malmsbury facility at 2.45pm on Wednesday and engaged in a series of violent assaults, car-jackings and robberies across the state.

Crimes allegedly linked to the 15 escapes included:

An attempted armed robbery in Berwick at 9.20pm on Wednesday, when offenders confronted a person and attempted to steal a car;

An assault in Bonbeach, where a man was assaulted by four men with a baseball bat and threatened with a knife at 10.45pm;

Two armed robberies in Noble Park at 11.15pm, where two victims were threatened with a knife and a baseball bat and had their phones stolen;

Hit and run at Mulgrave at 11.40pm involving a white Suzuki SUV stolen by four escapees that was later dumped at a BP service station on the corner of Springvale and Wellington roads;

Armed robbery at 12.30am outside Sexyland in Hallam, where a knife was used to threaten a staff member.

At 2.40am in Mitcham, three young men stormed into a home in Quarry Road and threatened the owner with a baseball bat and machete before demanding his phone and keys to a silver Mercedes.

The luxury car was found at an Ashburton property on Thursday morning, when four youths were apprehended by police. Several weapons, including bats and knives, were seized at the Ambon Street property by detectives.

At midday on Thursday, police raided a home in the Ballarat suburb of Redan and took a 17-year-old youth into custody.