Old evidence and new technology led to an arrest in a 25-year-old cold case, and to welcome closure for the victim’s family, Toronto police said Tuesday.

Surinder Singh Parmar was 38 when he was stabbed to death inside a gas station bathroom on Danforth Road on Nov. 19, 1990.

He had just arrived in Canada in July on a visitor’s permit and had left his wife and two children in India. Parmar was a schoolmaster with a PhD in history and was exploring Canada as a place for his family to live, Det. Sgt. Stacy Gallant said at a news conference.

His wife and children came to Ontario for the funeral and stayed.

Parmar’s children, now adults, “were shocked to get a phone call from police a few weeks ago,” Gallant said.

“To go 25 years without knowing who did this to their father was very difficult for them to cope with,” he added, saying the family would not be speaking to reporters.

Gallant said police opened up the case in August and re-examined old evidence.

Rupert Richards, 61, was arrested and charged with first-degree murder on Monday.

Richards, who lives alone in the west end, was unemployed at the time of the arrest. He is known to police. Richards, who would have been 36, was not a suspect at the time. While he was known to police, he had never been investigated for murder.

“He was surprised to see us there, from homicide. He was quite surprised,” Gallant said.

Police said the motive was likely robbery. Parmar was killed for a “small” amount of cash, Gallant said, but didn’t say how much.

The investigation into Parmar’s death is part of Project Never Give Up. Under that initiative, police are taking advantage of advancements in technology, especially DNA and fingerprint technology, to solve cold cases.

That’s what happened in Parmar’s case, but, detectives warn, not every case has evidence that can be re-examined.

Staff Insp. Greg McLane said that in other cases, “samples may be degraded thorugh the passage of time, or the collection method [used at the time] was not appropriate.”

McLane said that if a murder isn’t solved in three years, the homicide investigation is moved to the cold case team. While many cold cases have been reopened, tips from the public are still crucial, police said.

“We have a number of cases where we have the DNA of the person responsible, we just don’t have the name,” Gallant said.