Di social media murder tori of 13-year-old Olly

Na only wen dem kill Olly Stephens, for one field outside im house for Reading, na dat time im mama and papa realise di violent and disturbing world dia son bin dey exposed to thru im phone.

For BBC Panorama, reporter Marianna Spring investigate di role wey social media play for im death and expose how one 13-year-old social media account fit recommend violent videos and knives for sale.

Last January, Amanda and Stuart Stephens watch dia son from separate window as im comot from house, dem no sabi say dat go be di last time .

Olly waka go one field, Bugs Bottom, opposite dia house - im phone dey in hand.

Shortly afta, dem kill am.

Dat phone wey im bin dey hold later provide answers to wetin really happun.

Na two teenage boys stab Olly to death for one field behind im house, afta dem recruit one girl online to lure am go there.

Dem plan di whole attack on social media sake of one gbege wey happun for one social media chat group.

Im parents shock to discover di dark world of violence and hate wey dia son and im friends don get for dia phones. 

"Dem hunt am, track im and execute im thru social media," Olly papa, Stuart tell BBC.

"Social media no dey guilty of di murder, but e no do anytin to protect am, and without am, e go still dey here.”

Wetin happun di day Olly comot from house

Wen Olly comot di house dat day im reassure Amanda say im switch on im phone location, so she go sabi wia im dey.

Na di Sunday afta Christmas, and di family bin dey prepare to go back to work and school di next day. Amanda bin expect Olly back before dark.

But shortly afta e comot house, she hear knock on di door. Na one boy wey Olly sabi. Amanda no fit take in wetin im dey tok.

"I think am, 'Im just tok say dem stab Olly?'"

Stuart and Olly older sista run out to di field opposite dia home, wia Olly bin dey lie for pool of blood. Amanda follow dem.

"I just hold im hand and ask am make e no leave me," Stuart tok.

Friends, neighbours, dog walkers all try to help, but e don too late. E die for dat field. 

"I still look for im feet in di morning for di end of di bed bicos dem go always hang over di edge," Stuart say. As e no dey see am, e dey hit am evri time. 

Just before dem kill am, dem bin don diagnose Olly wit autism and at dat time, im dey mostly enjoy playing game and listening to music for im bedroom.

Di night afta im murder, wen dem look thru social media posts about Olly and screengrabs wey im friends share wit dia daughter, Stuart and Amanda begin to see di role wey social media don play for wetin happun.

Wetin police find out?

Detective Chief Inspector Andy Howard wey dey investigate di world inside dat phone say wetin dem see, dem no expect because 90% of di evidence for Olly murder trial come from mobile phone - and no child witnesses go need take di stand.

"We dey surprised by di amount of digital evidence," e tok.

We get enuf to convict two boys - age 13 and 14 at di time - of murder last November.

Dem convict di 13-year-old girl wey lead am to di park of manslaughter.

Wetin shock police first about di plenti videos, photos and screengrabs as dem begin to check, na di persona wey di 13- and 14-year-olds dem link to di case bin dey present online, e no follow wit di reality dem bin dey live.

E get photos dem share on Instagram of pipo wey dey hold knives, wit balaclavas and hoodies.

Di police also find videos as dem dey show off knives, and of boys dem link to Olly's murder as dem dey attack densef.

DCI Howard tell BBC Panorama say im believe dem bin dey share dis videos and photos "openly and very regularly" on Instagram and Snapchat.

E get one video dem post on Snapchat wey dey show attack wey dem dey call "patterning" and dis na wetin start di chain of events wey lead to Olly death.

Patterning na di humiliation of young pesin wey dem go film or photograph and den share am for social media. Na so dem go dey forward am dey go, share across different social media sites, to increase di embarrassment for di victim.

For di weeks before dem kill Olly, im bin don see an image of one younger boy wey dem humiliate and im try to alert di boy older brother as im forward di video give am.

Wen two boys wey dey one Snapchat group wit Olly sabi wetin happen, dem vex.

DCI Howard say di boys tink say Olly bin don dey "snitch (give dia gist out), dey grass on dem", and dis na wetin lead to di gbege.

Police also find hundreds of Snapchat voice notes from di two boys wey get gbas-gbos wit Olly. For dia dem discuss as dem wan attack Olly and try get one girl to set am up.

Di 13-year-old girl wey gree to do am sabi Olly for real life, and she bin meet di two boys involved online. Although all of dem dey live locally, dem meet for di first time on di day of di murder.

Di language wey di pipo dem convict use for di voice note dey shocking, wit comments like, "You go die tomorrow Olly," and "I go just give im bangs [hit him] or stab im." Wetin also dey worry na dia casual and cold tone.

For one voice note, di girl say, "[Male 2] wan make I set am up so den [Male 2] go bang im and pattern im and shit. I dey so happy, you no go understand.”

E no be like Snapchat pick up any of dis voice notes - and under di social media app own policy, e no dey possible to report one private message or voice note like dis to di site, only di account wey send am.

Di evidence wey police gada na just di informate dem need to prosecute – but DCI Andy Howard fear say dem don only scratch di surface for dis case.

For im eye, e dey likely say di children wey dey involved bin regularly dey exposed to violent content - and e no dey shake dem.

One recent study by di Huddersfield University Applied Criminology and Policing Centre back up dat idea, find am say social media na key factor for almost one quarter of crimes wey dey committed by under-18s.

Most of dis na acts of violence wey start wit online confrontation.