视频荧光文件与痕迹检验仪（SYJ-8 型）司法鉴定与刑事技术合规应用介绍
作者：毕思特科技 来源：毕思特科技 浏览数：3 发布时间：2026/4/22 9:11:23
视频荧光文件与痕迹检验仪（SYJ-8 型）司法鉴定与刑事技术合规应用介绍
【重要合规前置声明】本设备为法庭科学文件检验、痕迹检验、司法鉴定专用核心技术仪器，仅面向具备法定文件检验、痕迹检验鉴定资质的公安、检察、司法行政、司法鉴定等国家机关及授权鉴定机构定向研发、生产与销售，不向任何个人、无资质企业及非授权单位提供。本设备的设计、使用、校准与维护，严格遵循《中华人民共和国刑事诉讼法》《中华人民共和国司法鉴定程序通则》《法庭科学文件检验规范》《法庭科学印章印文检验规范》《法庭科学变造文件检验规范》等国家法律法规与行业技术标准，设备需符合司法鉴定机构资质认定、CNAS 实验室认可的相关技术要求，必须由依法登记的执业文件检验司法鉴定人、刑事技术专业人员规范操作，严禁无资质单位和个人违规使用，严禁因操作不规范、检验流程不合规导致的涉案检材损毁、鉴定证据失效、司法程序违法。
产品概述
SYJ-8 型视频荧光文件与痕迹检验仪，是一套集成多波段光源激发、高灵敏度光学成像、智能化专业图像分析技术于一体的综合性文痕检验专用平台，专为司法鉴定机构、公安刑事技术部门的文件真伪鉴定、潜在痕迹显现、微量物证检验工作深度定制，是文件检验专业的核心刑事技术取证设备。设备通过计算机集中控制，可输出从紫外到红外全波段的多种特定波长激发光源，搭配高精度专用滤光片组，对合同、票据、印章、证件、笔迹、微量痕迹等各类涉案检材进行全流程非破坏性检验与高清成像，可有效显现肉眼难以辨别的涂改变造痕迹、潜在压痕字迹、防伪特征、微量物证细节，为文件检验、痕迹鉴定工作提供客观、精准、可追溯的科学图像依据，是支撑司法鉴定意见科学性、保障鉴定结果法庭可采性的关键专用仪器，也是公安、检察、法院及第三方司法鉴定机构资质认定必备的标准化文检装备。
技术原理
系统核心基于物质光谱特性差异化原理工作，即不同物质（油墨、印泥、纸张、荧光防伪材料、书写墨迹等）对特定波段光波的吸收、反射、透射特性及荧光激发效应存在本质差异。设备通过进口可编程控制器，可精确选择并驱动卤钨灯、紫外灯、红外灯、激光光源等多类型光源，输出同轴光、侧光、透射光、紫外光、红外光、反斯托克斯激光等十种激发模式，以特定波长的光束定向照射待检验检材。
配套的高分辨率 CCD 摄像机，可精准采集检材在不同波段光波作用下产生的反射光、透射光与激发荧光图像，将光信号转换为高清数字信号后，通过高分辨率图像采集卡传输至主控计算机。最终经由专业文检图像处理软件，对采集图像进行几何校正、色彩分离、细节增强、噪声滤除、特征比对、精准测量等专业化处理，从而清晰显现肉眼无法识别的文件变造痕迹、潜在书写压痕、消退字迹、防伪特征等关键信息，全程不接触、不损坏检材原件，完美契合司法鉴定对检材原始性、检验过程非破坏性的核心要求。
核心功能与合规实战价值
设备搭载全波段集成化激发光源系统，标配 250W 均匀强光源、254nm 短波紫外 / 365nm 长波紫外光源、红外光源、透射光源、侧光、同轴光、980nm 反斯托克斯激光光源等十种激发模式，同时配备 400-550nm 多波段激发滤光片组，以及多规格截止式、带通式接收滤光片，可根据检材类型与检验需求，灵活组合光源波段与滤光片配置，全面覆盖朱墨时序鉴定、涂改痕迹显现、印章真伪比对、防伪特征检验等各类复杂文痕检验场景，哪怕是经过漂白、消退、遮盖、拼接的疑难变造文件，也可精准捕捉差异化光谱特征，显现被掩盖的原始信息。
设备配备高灵敏度专业图像采集系统，采用 1/3 英寸 IT CCD 摄像机，分辨率达 480 线，最低照度可达 0.014Lx，具备彩色与黑白模式手动切换功能。黑白模式可有效提升低反差单一墨迹检材的细节对比度，完美适配消退字迹、压痕字迹的显现需求；彩色模式可精准还原多色背景文件、多色墨迹、彩色防伪特征的光谱差异，适配朱墨时序、多色涂改文件的检验需求。搭配计算机控制的 10 倍连续光学变焦三可变镜头，可实现检材全貌到微观细节的无损放大成像，确保检材的每一处关键特征都能被清晰、完整采集，从源头保障鉴定数据的准确性与可靠性。
系统内置专业智能化文检图像处理软件，具备文件管理、标注测量、颜色处理、图像增强、噪声滤除、几何校正等全流程图像处理功能，特别集成了专业印章比对模块，支持拼接比对、重叠比对、特征点标注测量等多种专业比对方法，可精准完成印章印文的同一认定与种类认定。软件内置标准化鉴定表与鉴定报告自动生成功能，可直接将检验图像、特征比对结果、测量数据一键导入规范鉴定文书，实现检验流程、数据记录、报告出具的全流程标准化，大幅提升文件检验工作的效率与规范性，完全符合司法鉴定机构资质认定、CNAS 实验室认可对检验流程可追溯、鉴定文书规范化的核心管理要求。
系统采用计算机全流程集成化控制，所有光源模式切换、镜头变焦聚焦、滤光片选择、图像采集与存储，均通过计算机软件界面集中控制，由进口可编程控制器实现主机硬件的精准管理，每一步操作均可通过软件自动记录存档，确保检验全流程可追溯、可复核，杜绝人为操作误差导致的鉴定结果偏差。主光路采用一次折反设计，可有效避免光路偏移导致的图像变形，确保成像清晰稳定；系统运行稳定可靠，配套软件支持终身免费升级，可持续适配最新的文件检验行业标准与技术规范，保障设备长期的技术先进性与合规适用性。
合规应用场景
本设备仅可在具备法定文件检验、痕迹检验鉴定资质的机构内，由执业司法鉴定人、专业刑事技术人员规范操作，核心合规应用场景包括四大类：
一是文件伪造变造司法鉴定，针对合同纠纷、票据诈骗、职务侵占、民间借贷、遗嘱继承等案件中的可疑合同、借条、票据、遗嘱、学历证书、产权证明等文件开展检验，通过红外吸收、紫外荧光、光谱差异分析等技术手段，精准鉴别文件的添加、涂改、拼接、刮擦、漂白消退等变造痕迹，完成印章印文真伪鉴定、朱墨时序鉴定、笔迹形成时间鉴定、书写人同一认定，为案件定性、司法裁判提供关键的司法鉴定意见，是经济犯罪、民商事案件司法鉴定的核心技术支撑。
二是潜在痕迹显现与疑难物证检验，针对诈骗、贪污、泄密、间谍等案件中的检材，显现被化学试剂消退的字迹、密写墨水书写的隐蔽信息，揭示纸张上无墨迹的书写压痕内容，增强现场提取的模糊、残缺指纹、足迹细节，对案件现场提取的纤维、油漆碎片、墨粉颗粒等微量物证进行形态观察与特征固定，解决疑难物证的检验难题，为案件侦办提供关键线索与证据。
三是货币票据与证件防伪特征检验，针对伪造货币、伪造有价证券、伪造国家机关证件等案件，检验人民币、外币、汇票、支票、股票等有价证券的紫外荧光、红外吸收、同轴光等专业防伪特征，鉴别护照、身份证、驾驶证、营业执照等官方证件的真伪，精准识别伪造变造细节，为打击制假贩假、伪造证件等刑事犯罪提供科学的技术证据。
四是刑事技术与司法鉴定机构标准化实验室建设，作为公安刑事技术部门、检察院技术部门、司法鉴定机构文检实验室的标准配置仪器，是司法鉴定机构资质认定、CNAS 实验室认可登记必备的仪器设备，可用于各类文痕检材的系统性检验、电子档案规范化建立、鉴定流程全流程管控，同时可用于文件检验专业人员的技能培训与教学演示，支撑刑事技术与司法鉴定工作的标准化、规范化发展。
核心技术参数
设备成像系统搭载 1/3 英寸 IT CCD 摄像机，分辨率 480 线，最低照度 0.014Lx，扫描模式支持彩色与黑白模式手动切换；配套计算机控制的 10 倍连续光学变焦三可变镜头，可实现检材的无级放大成像。标配激发光源系统包含十种激发模式，分别为 250W 卤钨灯均匀强光源、6W 254nm 短波紫外光源、2×6W 365nm 长波紫外光源、2×20W 红外光源、3×6W 紫外 + 2×6W 白光透视光源、35W 侧光光源、20W 同轴光源、2W 980nm 反斯托克斯激光光源；配套 400-550nm 多波段激发滤光片组，以及多规格截止式、带通式接收滤光片，可灵活组合适配不同检验场景。控制系统采用计算机软件集中控制，通过进口可编程控制器实现主机硬件管理，配备高分辨率图像采集卡；配套专业图像处理软件，具备文件管理、标注测量、颜色处理、图像增强、专业印章比对、鉴定表自动生成等全套功能，支持终身免费升级；主机主光路采用一次折反设计，可保障成像清晰稳定，无畸变、无偏移。
合规实战应用案例
- 某市人民检察院委托司法鉴定中心，对一起涉案金额超 5000 万元的合同诈骗案件中的涉案《购销合同》《担保协议》进行文件检验鉴定，案件核心争议焦点为合同上的公司印章印文真伪，以及印文与打印字迹的朱墨时序，直接决定案件的定性与罪与非罪的认定。由于涉案合同存在多处局部涂改，印文与字迹存在大面积重叠，传统检验设备无法清晰呈现印文与字迹的交叉层次，也无法精准捕捉印文的细节特征，检验工作一度陷入僵局。鉴定人使用 SYJ-8 型视频荧光文件与痕迹检验仪，通过红外光源与紫外荧光光源的组合切换，配合专用滤光片，清晰分离了印泥与打印墨迹的光谱差异，明确了印文形成时间晚于打印字迹的核心事实；同时通过 10 倍光学变焦放大成像，完整提取了印文的 16 处防伪细节特征，与备案真实印文进行重叠比对、特征点测量，最终出具了 “涉案合同印章印文系伪造、印文形成于打印字迹之后” 的司法鉴定意见。检察机关依据该鉴定意见，以合同诈骗罪对被告人依法提起公诉，该鉴定意见被法院全部采纳，成为案件定罪量刑的核心证据，本设备的高灵敏度成像、光谱差异化检验能力，为本次疑难文件检验鉴定提供了关键技术支撑。
- 某市公安局刑事技术支队受理一起票据诈骗案件，犯罪嫌疑人通过化学消退方式，将银行转账支票的小写金额 “1 万元” 篡改为 “100 万元”，骗取企业巨额资金，案件侦办的核心是获取支票被涂改变造的关键物证。由于犯罪嫌疑人使用专业漂白试剂消退原始字迹，并使用同色墨水重新书写，肉眼与常规放大镜完全无法识别变造痕迹，原始字迹消退彻底，常规检验手段无法显现。检验人员使用 SYJ-8 型视频荧光文件与痕迹检验仪，通过短波紫外光源、反斯托克斯激光光源的组合激发，配合专用接收滤光片，成功显现了被漂白消退的原始 “1 万元” 字迹，清晰还原了支票的涂改变造过程，同时通过侧光与同轴光的切换，完整固定了支票纸面的刮擦痕迹，获取了犯罪嫌疑人变造票据的完整物证。侦查人员依据该检验结果，锁定了犯罪嫌疑人的作案手法与关键证据，最终成功抓获犯罪嫌疑人，破获了该起重大票据诈骗案件，本设备的潜在痕迹显现能力，为案件的侦破与定罪提供了决定性的科学证据。
Application Introduction of Video Fluorescence Document and Trace Inspection Instrument (Model SYJ-8)
【Important Compliance Pre-Declaration】This equipment is the core professional technical instrument dedicated to forensic science document examination, trace inspection and judicial authentication. It is only developed, produced and sold for state organs and authorized authentication institutions with legal document examination and trace inspection qualifications, including public security organs, procuratorates, judicial administrative organs, and judicial authentication institutions, and will not be provided to any individual, unqualified enterprise or non-authorized unit. The design, use, calibration and maintenance of this equipment strictly comply with national laws, regulations and industry technical standards such as the Criminal Procedure Law of the People's Republic of China, General Rules for Judicial Authentication Procedures of the People's Republic of China, Forensic Science - Specification for Document Examination, Forensic Science - Specification for Seal Impression Examination, and Forensic Science - Specification for Altered Document Examination. The equipment must meet the relevant technical requirements of qualification accreditation of judicial authentication institutions and CNAS laboratory accreditation, and must be operated in a standardized manner by legally registered practicing forensic document examiners and criminal technology professionals. It is strictly prohibited for unqualified units and individuals to use it in violation of regulations, and it is strictly prohibited to cause damage to involved samples, invalidation of judicial authentication evidence and violation of judicial procedures due to irregular operation and non-compliant inspection process.
Product Overview
The Video Fluorescence Document and Trace Inspection Instrument (Model SYJ-8) is a comprehensive professional platform for document and trace inspection integrating multi-band light source excitation, high-sensitivity optical imaging and intelligent professional image analysis technology. It is deeply customized for the authenticity identification of documents, potential trace development, and micro physical evidence inspection of judicial authentication institutions and public security criminal technology departments, and is the core criminal technology evidence collection equipment for the document examination major. Through the centralized control of the computer, the equipment can output a variety of specific wavelength excitation light sources from ultraviolet to infrared, matched with a high-precision special filter set, to carry out full-process non-destructive inspection and high-definition imaging of various involved samples such as contracts, bills, seals, certificates, handwriting, and micro traces. It can effectively display altered traces, potential writing indentations, anti-counterfeiting features, and micro evidence details that are difficult to distinguish by the naked eye, providing objective, accurate and traceable scientific image basis for document examination and trace identification work. It is a key special instrument to support the scientificity of judicial authentication opinions and ensure the court admissibility of identification results, and also a standardized document examination equipment necessary for the qualification accreditation of public security, procuratorate, courts and third-party judicial authentication institutions.
Technical Principle
The core of the system works based on the principle of differential spectral characteristics of substances, that is, different substances (ink, ink paste, paper, fluorescent anti-counterfeiting materials, writing ink, etc.) have essential differences in the absorption, reflection, transmission characteristics and fluorescence excitation effect of light waves of specific bands. The equipment can accurately select and drive various types of light sources such as halogen tungsten lamp, ultraviolet lamp, infrared lamp and laser light source through an imported programmable controller, and output ten excitation modes including coaxial light, side light, transmitted light, ultraviolet light, infrared light, and anti-Stokes laser light, to irradiate the sample to be inspected with a light beam of a specific wavelength.
The matched high-resolution CCD camera can accurately collect the reflected light, transmitted light and excited fluorescence image of the sample under the action of light waves of different bands, convert the optical signal into high-definition digital signal, and transmit it to the main control computer through the high-resolution image acquisition card. Finally, through the professional document examination image processing software, the collected images are professionally processed such as geometric correction, color separation, detail enhancement, noise filtering, feature comparison, and accurate measurement, so as to clearly display the key information such as document alteration traces, potential writing indentations, faded handwriting, and anti-counterfeiting features that cannot be recognized by the naked eye. The whole process does not contact or damage the original sample, which perfectly meets the core requirements of judicial authentication for the originality of the sample and the non-destructive nature of the inspection process.
Core Functions and Compliance Practical Value
The equipment is equipped with a full-band integrated excitation light source system, which is standard equipped with ten excitation modes including 250W uniform strong light source, 254nm short-wave ultraviolet/365nm long-wave ultraviolet light source, infrared light source, transmitted light source, side light, coaxial light, 980nm anti-Stokes laser light source. It is also equipped with a 400-550nm multi-band excitation filter set, as well as multi-specification cut-off and band-pass receiving filter sets. According to the type of sample and inspection requirements, it can flexibly combine the light source band and filter configuration, fully covering various complex document and trace inspection scenarios such as ink-seal sequence identification, altered trace development, seal authenticity comparison, and anti-counterfeiting feature inspection. Even for difficult altered documents that have been bleached, faded, covered and spliced, it can accurately capture the differential spectral characteristics and display the hidden original information.
The equipment is equipped with a high-sensitivity professional image acquisition system, using a 1/3 inch IT CCD camera with a resolution of 480 TV lines, a minimum illumination of 0.014Lx, and supports manual switching between color and black and white modes. The black and white mode can effectively improve the detail contrast of low-contrast single ink samples, which is perfectly suitable for the development needs of faded handwriting and indented handwriting; the color mode can accurately restore the spectral differences of multi-color background documents, multi-color ink, and color anti-counterfeiting features, which is suitable for the inspection needs of ink-seal sequence and multi-color altered documents. Matched with a 10x continuous optical zoom three-variable lens controlled by computer, it can realize lossless magnification imaging from the full view of the sample to the micro details, ensuring that every key feature of the sample can be collected clearly and completely, and guaranteeing the accuracy and reliability of the identification data from the source.
The system has built-in professional intelligent document examination image processing software, which has full-process image processing functions including file management, annotation and measurement, color processing, image enhancement, noise filtering, and geometric correction. It specially integrates a professional seal comparison module, and supports a variety of professional comparison methods such as splicing comparison, overlapping comparison, and feature point annotation and measurement, which can accurately complete the individual identification and type identification of seal impressions. The software has built-in standardized identification form and automatic generation function of identification report, which can directly import the inspection images, feature comparison results and measurement data into the standardized identification documents with one click, realizing the standardization of the whole process of inspection process, data recording and report issuance, greatly improving the efficiency and standardization of document inspection work, and fully complying with the core management requirements of qualification accreditation of judicial authentication institutions and CNAS laboratory accreditation for the traceability of inspection process and standardization of identification documents.
The system adopts computer full-process integrated control. All light source mode switching, lens zoom and focus, filter selection, image acquisition and storage are centrally controlled through the computer software interface, and the precise management of the host hardware is realized by the imported programmable controller. Each operation can be automatically recorded and archived by the software, ensuring that the whole inspection process is traceable and reviewable, and eliminating the identification result deviation caused by human operation errors. The main optical path adopts a one-time reflection design, which can effectively avoid image deformation caused by optical path offset and ensure clear and stable imaging. The system runs stably and reliably, and the supporting software supports lifelong free upgrade, which can continuously adapt to the latest document inspection industry standards and technical specifications, and guarantee the long-term technical advancement and compliance applicability of the equipment.
Compliant Application Scenarios
This equipment can only be operated in a standardized manner by practicing judicial appraisers and professional criminal technical personnel in institutions with legal document inspection and trace inspection qualifications. The core compliant application scenarios include four categories:
First, judicial authentication of forged and altered documents. For the inspection of suspicious contracts, IOUs, bills, wills, academic certificates, property right certificates in cases such as contract disputes, bill fraud, duty encroachment, private lending, and will inheritance, through technical means such as infrared absorption, ultraviolet fluorescence, and spectral difference analysis, it can accurately identify the altered traces such as addition, alteration, splicing, scraping, bleaching and fading of the documents, complete the authenticity identification of seal impressions, ink-seal sequence identification, handwriting formation time identification, and writer identification, providing key judicial authentication opinions for case characterization and judicial judgment. It is the core technical support for judicial authentication of economic crimes and civil and commercial cases.
Second, potential trace development and difficult physical evidence inspection. For samples in cases such as fraud, corruption, leakage of secrets, and espionage, it can develop the handwriting faded by chemical reagents, hidden information written in secret writing ink, reveal the content of writing indentations without ink on the paper, enhance the details of blurred and incomplete fingerprints and footprints extracted from the scene, and carry out morphological observation and feature fixation of micro evidence such as fibers, paint fragments, and toner particles extracted from the crime scene, solving the inspection problems of difficult physical evidence and providing key clues and evidence for case investigation.
Third, anti-counterfeiting feature inspection of currency bills and certificates. For cases of counterfeiting currency, counterfeiting valuable securities, and forging state organ certificates, it can inspect the professional anti-counterfeiting features such as ultraviolet fluorescence, infrared absorption, and coaxial light of RMB, foreign currency, bills of exchange, checks, stocks and other valuable securities, identify the authenticity of passports, ID cards, driver's licenses, business licenses and other official documents, accurately identify the details of forgery and alteration, and provide scientific technical evidence for combating criminal crimes such as counterfeiting and selling fake goods, and forging certificates.
Fourth, standardized laboratory construction of criminal technology and judicial authentication institutions. As the standard configuration instrument of the document examination laboratory of public security criminal technology departments, procuratorate technical departments, and judicial authentication institutions, it is a necessary instrument for the qualification accreditation of judicial authentication institutions and CNAS laboratory accreditation. It can be used for the systematic inspection of various document and trace samples, standardized establishment of electronic archives, and full-process management of the identification process. At the same time, it can be used for skill training and teaching demonstration of document examination professionals, supporting the standardized and standardized development of criminal technology and judicial authentication work.
Core Technical Parameters
The imaging system of the equipment is equipped with a 1/3 inch IT CCD camera, with a resolution of 480 TV lines, a minimum illumination of 0.014Lx, and the scanning mode supports manual switching between color and black and white modes; it is matched with a 10x continuous optical zoom three-variable lens controlled by a computer, which can realize stepless magnification imaging of the sample. The standard excitation light source system includes ten excitation modes, which are 250W halogen tungsten lamp uniform strong light source, 6W 254nm short-wave ultraviolet light source, 2×6W 365nm long-wave ultraviolet light source, 2×20W infrared light source, 3×6W ultraviolet + 2×6W white light transmission light source, 35W side light source, 20W coaxial light source, 2W 980nm anti-Stokes laser light source; it is matched with 400-550nm multi-band excitation filter set, as well as multi-specification cut-off and band-pass receiving filter sets, which can be flexibly combined to adapt to different inspection scenarios. The control system adopts centralized control by computer software, and realizes host hardware management through imported programmable controller, equipped with high-resolution image acquisition card; the supporting professional image processing software has a full set of functions including file management, annotation measurement, color processing, image enhancement, professional seal comparison, and automatic generation of identification forms, supporting lifelong free upgrade; the main optical path of the host adopts a one-time reflection design, which can ensure clear and stable imaging without distortion and offset.
Practical Application Cases
- The Judicial Authentication Center entrusted by the People's Procuratorate of a city carried out document examination and authentication of the involved Sales and Purchase Contract and Guarantee Agreement in a contract fraud case with an involved amount of more than 50 million yuan. The core dispute focus of the case was the authenticity of the company's seal impression on the contract, as well as the ink-seal sequence of the seal impression and the printed handwriting, which directly determined the characterization of the case and the determination of guilt or innocence. Because there were many partial alterations in the involved contract, the seal impression and the handwriting had a large area of overlap, the traditional inspection equipment could not clearly present the cross level of the seal impression and the handwriting, nor could it accurately capture the detailed features of the seal impression, so the inspection work was once in a deadlock. The judicial appraiser used the Video Fluorescence Document and Trace Inspection Instrument (Model SYJ-8), through the combined switching of infrared light source and ultraviolet fluorescence light source, matched with a special filter, clearly separated the spectral difference between the ink paste and the printed ink, and clarified the core fact that the seal impression was formed later than the printed handwriting. At the same time, through 10x optical zoom magnification imaging, 16 anti-counterfeiting detailed features of the seal impression were completely extracted, and overlapping comparison and feature point measurement were carried out with the real seal impression filed. Finally, the judicial authentication opinion that "the seal impression on the involved contract is forged, and the seal impression was formed after the printed handwriting" was issued. Based on this authentication opinion, the procuratorate initiated a public prosecution against the defendant for the crime of contract fraud, and the authentication opinion was fully adopted by the court, becoming the core evidence for the conviction and sentencing of the case. The high-sensitivity imaging and spectral differential inspection capabilities of this equipment provided key technical support for this difficult document examination and authentication.
- The Criminal Technology Detachment of the Municipal Public Security Bureau accepted a bill fraud case. The suspect altered the lowercase amount "10,000 yuan" on the bank transfer check to "1,000,000 yuan" through chemical fading, defrauding the enterprise of a huge amount of money. The core of the case investigation is to obtain the key physical evidence of the altered check. Because the suspect used professional bleaching reagent to fade the original handwriting and rewrote it with the same color ink, the naked eye and conventional magnifying glass can not identify the altered traces at all, the original handwriting was completely faded, and the conventional inspection means can not be developed. The inspectors used the Video Fluorescence Document and Trace Inspection Instrument (Model SYJ-8), through the combined excitation of short-wave ultraviolet light source and anti-Stokes laser light source, matched with a special receiving filter, successfully developed the original "10,000 yuan" handwriting faded by bleaching, clearly restored the alteration process of the check, and at the same time, through the switching of side light and coaxial light, completely fixed the scraping traces on the check paper, and obtained the complete physical evidence of the suspect altering the bill. Based on the inspection results, the investigators locked the suspect's modus operandi and key evidence, finally successfully arrested the suspect and solved the major bill fraud case. The potential trace development capability of this equipment provided decisive scientific evidence for the detection and conviction of the case.