Sajad Chaudhury told a district judge at Bradford Magistrates Court that Procter denies the charge of murdering her son.
He said: 'Clearly, it's a horrific and traumatic incident for all people involved and the defendant's family is in court supporting her. This is a defendant who denies the charge of murder.'
Continuing, Chaudhury said, 'The incident happened around 5pm. It's very important for any witnesses to come forward who have any CCTV or any video footage on their phones or who have seen anything in terms of behaviour from anyone in the days leading up to the incident.
'That may relate to witnesses on the sixth floor and below. We are asking for any footage to be handed into them [the police] and any witnesses to come forward.'
Neighbours claim Procter was living in the flat with parter Luke Green, 21, the toddler and a baby daughter.
Residents spoke of the horrific moment they saw the baby fall to his death.
Witness Danuta Tomaszewicz, 59, said the little boy was naked when her husband and a friend went to help.
She had been on her phone, looking out of the window from the first floor flat that they are decorating when she suddenly noticed the child on the ground below.
Mrs Tomaszewicz at first thought it was a doll.
Her niece Monika Tomaszewicz said: 'She realised it was a real baby when she saw he was trying to catch his breath and his belly was moving.
Another helper rang 999 and an ambulance arrived 20 minutes later, the niece said.
The case remains ongoing, with Procter due for sentencing later in the week.