The teenager apprehended by the CBI connection with the murder of Ryan International School student Pradhuman had apparently come under the scanner of the agency within six days of its taking over the case.
The agency in an intimation to a court in Gurgaon on September 29 had said that it had carried out searches at the residence of the father of the suspect the previous day and sought permission to retain articles seized by it which was granted by the court.
The searches were kept secret by the CBI which was trying to get more evidence about the alleged involvement of the teenager.
When asked whether the teenager was considered a suspect during the probe, the agency, which took over the case on September 22, remained tight lipped on the order.
Pradhuman, the Class 2 student, was found near the toilet of Ryan International School with his throat slit on September 8 morning within an hour of his father leaving him at the school.
Sources said the agency is also looking at the possibility of involvement of some more people but it has not questioned or detained anyone in this regard so far.
The suspect who was taken into custody on Tuesday night was taken by the CBI to the shop in Sohna from where he had purchased knife allegedly used in the murder of Pradhuman, the sources said.
They said the agency has also purchased some knives from the shop to get their forensic analysis done in order to corroborate if the weapon was actually bought from there.
The shopkeeper has reportedly told the CBI team that a large number of people purchase such knives and it will be difficult to remember someone.
The agency today kept questioning the teenager for nearly seven hours on various aspects of the case including how he got the idea to kill someone to get examination and parents teacher meeting delayed, what he did after the crime, whom he spoke to and whether he confide in others, they said.
The CBI will submit its report tomorrow before the juvenile court where it will present the teenager as the duration of his custody is coming to an end.
The sources said the agency is trying to analyse all the possibilities which could have triggered the murder.
In a sensational twist to the case, the agency recently announced that it had apprehended the senior student in connection with the murder of Pradhuman rejecting Gurgaon police's theory that the killing was the handiwork of school bus conductor Ashok Kumar.
According to the agency, the Class 11 student, believed to be weak in his studies, allegedly slit Pradhuman's throat to get the school to declare a holiday in order to defer a scheduled parent-teacher meeting (PTM) and an examination.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)