Despite the release of a photo this morning, police in B.C. say they have more questions than answers about an apparently homeless man charged in the fatal stabbing of a teen girl at her Abbotsford high school.

"We need to determine who knows him, who knows of him, his history and anything about him for that matter," Staff Sgt. Jennifer Pound, spokeswoman for the Integrated Homicide Investigation Team, said on Wednesday.

Homicide investigators said yesterday that Gabriel Brandon Klein, 21, has been charged with second-degree murder in the death of 13-year-old Letisha Reimer.

It is rare that we don't have a lot of those details about an individual. — Staff Sgt. Jennifer Pound

Klein has also been charged with aggravated assault in the stabbing of a 14-year-old girl, who was injured in Tuesday's attack. That girl is recovering in hospital and there is a publication ban on her name.

Despite having had Klein in custody since Tuesday afternoon, it took police until Thursday to release a photo of him.

The image was captured by a security camera at an undisclosed location just hours before the attack at the high school, police say.

Wanted in Alberta

Police in B.C. said earlier Klein did not appear to have a criminal history and released vague details about his recent whereabouts.

"Mr. Klein is of no fixed address and has been known to frequent the Vancouver area since February/March of this year," said Pound. Before that he was "known to be in the Alberta area."

CBC News has confirmed that a man of the same name and age faced four traffic charges in Calgary between 2014 and 2015.

The charges were three counts of tampering with a vehicle and one of boarding public transit without a valid pass. That man did not appear in court for any of the charges. He was convicted and a warrant was issued for his arrest.

CBC News also learned that, at the time of the latter offence, that man had an Edmonton address.

Klein also spent time in Downtown Vancouver's Covenant House, but a spokesperson said they couldn't offer any details while they cooperate with Abbotsford Police in the investigation.

Court records show a man with the same name and age as Gabriel Klein gave this Edmonton building on 62 Street NW as his address for a 2015 traffic infraction in Calgary. (Meghan Grant/CBC)

Motive remains a mystery

Investigators have also said very little about what might have motivated the attack.

"Although it is early, evidence suggests this incident to be random,"said Pound, echoing remarks made earlier by school officials.

"We do not believe the suspect has ties to this school, or to the two girls, or specifically to the Abbotsford area," she said.

"There is very little information we have on Mr. Klein and for that reason we are asking for the public's assistance," she added.

Police spokeswoman Staff Sgt. Jennifer Pound said investigators have few details on the suspect in the Abbotsford stabbings. (CBC)

Uncommunicative, uncooperative

Meanwhile a Crown prosecutor told a provincial court judge on Wednesday that Klein was unable to appear at his first scheduled court appearance because he was being restrained for his own safety in a holding cell.

The prosecutor said Klein was admitted to hospital on Tuesday after his arrest, certified under the Mental Health Act by one doctor and then decertified by a psychiatrist the next day.

He also said Klein was uncommunicative, uncooperative and unwilling to walk up from cells under the courthouse to attend his hearing.

Abbotsford Senior Secondary School remained behind police tape on Wednesday as police continued their homicide investigation. (Rafferty Baker/CBC)

For her part, Pound would only say police are looking into mental health concerns.

"That is certainly going to be part of our investigation," she said. "I can tell you right now he is not in medical care. He is in police custody, but further assessment on that regard will have to be done."

Meanwhile police are asking the public to stop circulating a video of the attack that appears to show the assailant. Like many media outlets CBC received a copy of the video as news was breaking of the attack, but chose not to publish it.

Police ask anyone with information about Klein to call the homicide tip line at 1-877-551-4448, or call CrimeStoppers to remain anonymous.