When someone writes on a sheet of paper, the pen pressure leaves invisible impressions on the sheets underneath. These indented impressions can be recovered with an Electrostatic Detection Apparatus (ESDA), a sensitive and non-destructive technique.
Recovered impressions can show what was written on a missing page, whether a document was written in the sequence claimed, and whether pages come from the same pad or notebook.
What we examine
- Recovery and decipherment of indented writing
- Sequence of writing and of entries in registers or diaries
- Linking pages to the same pad, notebook or writing session
- Testing whether a document was written when and where it is claimed
Typical matters
- Notebooks, diaries, registers and logbooks
- Statements and minutes said to have been written at a particular time
- Anonymous letters and threats
- Missing or destroyed pages
What we need from you
- The original documents. ESDA cannot be done on a copy or scan
- Handle as little as possible and keep the documents flat and dry
Scans first, originals later. You can send high-resolution scans through oursecure upload page for a first assessment and a quotation. Please keep the originals safe, flat and unmarked until we arrange secure delivery.
Questions
Does ESDA leave marks on the document?
No. ESDA is non-destructive and does not change the document. It should be done before any other test that could affect the paper surface, so contact us before submitting documents to other examinations.