A former New York police officer working as a school teacher's aide has been charged with murder over the fatal stabbing of jogger Katie Suarez in Brooklyn, and has been ordered held without bail after his arraignment.

Sayed Mohassib, 27, was arrested at his home in Bensonhurst on Saturday, a week after Suarez, 28, was attacked while out running on the Shore Parkway greenway beside the Belt Parkway in Brooklyn. Police said he faces charges of second-degree murder, tampering with physical evidence and criminal possession of a weapon.

Suarez, a bank teller and keen runner, was attacked on the evening of 30 October. Her father found her injured on the path, and she was taken to hospital with a stab wound to her neck. She later died. Her mother, Yasira, had appealed during the search for her attacker, saying: "You took an angel."

According to a criminal complaint reported by the New York Post, Mohassib told detectives he had gone to the bike path carrying a knife because he believed people were going to come and kill his family. He claimed he left the park, went to the nearby Verrazzano Bridge, returned, sat on a bench and became covered in blood. He also told officers he "did not stab anyone", the complaint said.

Investigators said surveillance video captured a man walking towards the crime scene and later running from it in a sequence that fitted the attack. Law-enforcement sources told the Post that Mohassib was identified using facial-recognition technology combined with fingerprints and photographs already held in government systems from his time with the police and the city's education department. The complaint said he later identified himself on the video footage.

The complaint also said Mohassib told officers he had got rid of bloody clothing and the knife, and that he had blood on his hands and in his apartment, which he had tried to clean. Detectives are now searching a sanitation barge for the murder weapon, according to sources cited by the Post. Inside the suspect's room, the complaint said, the walls were splattered with blood.

Mohassib spent about six weeks with the New York Police Department before leaving to join the United States Marine Corps, only to be turned away over concerns about his mental state, sources told the Post. He later tried to return to the police but was turned down, the sources said. At the time of the attack he was working as a paraprofessional, or teacher's aide, at Public School 200 in Brooklyn, a short distance from the greenway where Suarez was attacked.

The New York City Department of Education said it had suspended him and would seek to end his employment. "The safety of our students is our very top priority. We have suspended this individual and will move to terminate employment pending the outcome of the conviction," the department said, adding that it was supporting the police investigation.

His employment in a school has prompted questions from elected officials. City Council member Kayla Santosuosso, State Senator Andrew Gounardes and Assembly member-elect Chris McCreight said in a joint statement that it was troubling that a man they described as evidently mentally disturbed, with no criminal record, had been working as a teacher's aide, and that the circumstances of his hiring and continued employment warranted a full investigation.

Police have not publicly set out a motive for the killing, and the charges against Mohassib are allegations. He has not been convicted of any offence. He was arraigned on Saturday and ordered held without bail, and he did not answer questions as officers escorted him from the 62nd Precinct, wearing flip-flops and a red jacket.

The attack prompted shock across New York and an intensive search for the attacker, with runners on the greenway describing relief at the arrest and hope of closure for Suarez's family. Court proceedings in Brooklyn are expected to continue in the coming days.