This impressive play is the second in four months to plunge into the whirlpool of evidence concerning the killing of Jean Charles de Menezes in July 2005. The story goes that Nicolas Kent, the artistic director of the Tricycle, was unable to buy a seat for Kieron Barry’s Stockwell during its sell-out run at the Landor in the summer and decided that the only way he could see it was to arrange a transfer to his own theatre.

That the case continues to exert outrage and dismay is no surprise — the 503 Theatre (above the Latchmere pub in Battersea) was packed when I attended the last preview of this further exposure of the truths and untruths, panic and incompetence surrounding the death of this innocent Brazilian. We will presumably be offered yet another version with the publication this week of Policing Controversy by Sir Ian Blair, the Commissioner of the Metropolitan Police at the time of the wretched business.

Mistakes will happen, and it has to be remembered that only a fortnight before his death at Stockwell Underground station terrorist bombs had killed and injured more Londoners on a single day than since the height of the Blitz. But it isn’t so much the panic in the police force before the killing as the panic afterwards that still prompts dismay and anger: the denials, the untruths and nastiest of all, perhaps, attempts to besmirch the dead man’s character.

Where Barry restricted himself to transcripts of the inquest for his play, Paul Unwin and Sarah Beck have gone outside the courtroom to interview friends and family, lawyers and even senior police officers. These include Andy Hayman, the former Assistant Commissioner under Sir Ian, whose contributions here are numerous. The facial expressions and tone of voice that Gerald Kyd adopts when playing him are illuminating.

Another major contributor is Michael Mansfield, QC, counsel for the de Menezes family, given a steely precision in a fine performance by Justine Waddell. All members of the cast play numerous characters, and on occasion the jumps between them are unclear. Yet this scarcely matters amid the continuing whirl of grief and shock.

Beck has previous experience in verbatim drama, and Unwin’s long CV includes co-creating Casualty and Holby City. The two know how to create from diverse testimony a dramatic whole, ranging between group uproar and isolated speeches, which themselves range between the carefully precise, the self-serving and the grief-stricken. Tim Roseman’s direction also uses numerous theatrical approaches, including video projections, adroit changes in pace and even Pirandellian interruptions.

With its emphasis on the tragedy’s human cost in shock and sorrow This Much is True gives us a clear-eyed glimpse of what lay behind the official reports and misreporting.

Box office: 020 7978 7040, to Nov 21

Editor's choice

• The super cool Vampire Weekend
• Streep and Baldwin get complicated
• Guy Ritchie on Sherlock Holmes