Whether the crime was committed yesterday or 30 years ago, the officers in the Domestic Abuse Taskforce are looking for them.
Before most people have even had their cornflakes, the Taskforce's 14 officers are preparing to knock the doors of serial offenders. The officers have often spent months researching and gathering evidence on the crimes from neighbours, current and ex-partners, through technology or even medical notes.
The Evening Times joined officers as they caught one 50-year-old man who was questioned and then arrested in connection with domestic abuse offences.
The operation started with a briefing at the Taskforce headquarters in the East End. The five plain-clothed officers, led by Detective Inspector Craig Willison, gathered round the table to discuss two suspects they had been researching for months and whom they hoped to detain that day.
Before long, the team joined the early morning commuters as they drove through the city to an address in Renfrew in an attempt to take their first suspect in for questioning.
As officers arrived, Detective Sergeant Susie Cairns, said: "We target people early so they do not expect it and then they have nowhere to hide.
"We have 45 live inquiries at the moment – and they are a mix of people.
"There are people who work 9-5 so we need to get them before they start or there are people who could be at a number of addresses.
"But to get to the point where we are going out to detain someone means we have done a lot of digging and we have as much evidence as possible."
When we arrived at the cul-de-sac, one officer was deployed to the rear while others knocked at the front door.
But it was bad news. The 23-year-old was out of the country.
"His mum was really nice and told us everything," said one of the team, failing to hide the disappointment on his face. It later emerged the man had been in contact with the taskforce HQ to arrange a time to go in and talk to them when he returned.
However, no time is wasted because as the two cars travelled to the next location in Stewarton, Ayrshire.
As the cars bumped along the windy roads, Detective Sergeant Cairns, who has worked in child protection, CID and the policy side of domestic abuse, said: "This is a historical case that we have been speaking to ex-partners about.
"Some people are shocked if we want to interview them about something in the past. But abuse is abuse whenever it is done."
The team called for back-up as we approached the location because this suspect was known to local officers. "He is a well built guy," one of the officers said.
With everyone in place, the officers approached the house and knocked on the door.
The rest of the team, who were waiting behind a wall so as not to give the game away, waited before a call came through to say they were in.
A few minutes later the man, wearing a hoodie and hat, was then led out of his home wearing handcuffs, placed in the unmarked car and driven to the police station.
Back at the office, Detective Inspector Willison, explained that the role of the taskforce, which was set up in 2009 and is the first of its kind in the UK, is to focus on the perpetrator.
"We look at the high tarriff (serial) offenders, the ones that cause victims and their families most concern," he said.
"Domestic abuse is our main focus. However if that individual is a domestic abuser, drug dealer, knife carrier or drink-driver, that person will be targeted on the whole big package."
The unit sits fortnightly with partner agencies, including the Glasgow-based Advocacy Support, Services, Information Together (Assist) and Women's Aid, who support victims, and the Crown Office, to share information.
Detective Inspector Willison added: "One of our main objectives is to reduce domestic homicide and we do that by early intervention.
"We have cases where people have abused six, seven or eight partners. We will go back and will ask the questions to these partners.
"Have you ever been abused by this person? That has been one of our major successes because there have been a lot of uncovered incidents. People do tell us about it."
The taskforce counts a number of high profile cases as successes:
l William Lynn was jailed and put on a lifelong restriction order at the High Court in Glasgow in March for the rape and domestic abuse against four women over 20 years.
l Joseph Loughran, who lived in Drumchapel, was locked up last August for 9½years after admitting a string of brutal attacks on five women over 29 years.
l Raymond Donnelly was imprisoned for 15 years in July last year for raping and attacking women in Glasgow and Ayrshire between 1997 and 2010.
Each of these cases took months to investigate.
Detective Inspector Willison said: "With each of these people there was a current victim.
"We uncovered previous victims and built a big picture of domestic abuse. It led to the cases going to the High Court.
And he admitted it is "satisfying" to see people pay the price for abusing because "you know you are taking the risk of harm away from the victim".
He added: "They have lived a life of torture and we have removed that.
"When it gets to a trial it gives the victim empowerment because they get to see justice being done. It amazes us how strong the victims are."