《我国足迹检验技术的回顾与展望》
关键词：足迹 回顾
足迹，是在犯罪现场上遗留率最高的一类痕迹。世界上许多国家的警察机关对犯罪现场遗留足迹的研究和利用都很重视。我国公安机关对足进的研究己经达到了什么水平?这是本文所要介绍的中心内容，
一、我国足迹检验技术经历了三个发展阶段
我国记录和利用犯罪遗留足迹的历史，可以追溯到先秦时期。但长期以来处在简单的、种类识别的范畴，对我们现在的足迹检验技术并无很大影响。我国足迹检验技术的发展与成熟，是在新中国成立以后。建国以来，我国足迹检验经历了三个发展阶段。
1、初创阶段。五十年代，我们吸收了原苏联《犯罪对策学》中足迹检验的理论与方法，创建了我国公安机关自己的足迹检验工作。这个阶段的主要特点，是以足迹中的形象特征检验为主体。所谓"形象特征"主要指鞋底表面的大小、花纹、磨损及修补的细小形态等;也括赤足底的脚纹(但现场较少见)。这时的足迹检验主要认定的对象是犯罪人到现场时所穿的鞋，而不能直接认定人。到五十年代后期，我国痕捡工作者从实战需要出发，总结办案中的实践经验，研究了人的赤足印不同区域的形态特点，把趾、掌、弓、踵各部位形状、大小、排列特征作了详尽的归纳，提出了脚纹之外的其他赤足印特征可以认定人身的理论与方法，实践应用很好，并沿续至今。可以说，在初创阶段后期，我们已有了自己的发展。
足迹的形象特征检验，是我国足进检验技术发展的基础，现仍是我国足迹检验体系中的重要组成部分。它在我国几十年的刑侦实践中发挥了巨大的作用。
2、创新阶段。从一九五九年开始，公安部和内蒙公安厅发现和总结了以马玉林同志为代表的民间“码踪”经验，通过认其考察与研究，推广和普及了“步法追踪”技术。“步法”是人行走运动的习惯性规律。它所研究的步幅、步态，都反映了行走过程中脚对地面作用力的特点。这就抛开了鞋底形象特征，抓住了每个人长期形成的落脚、碾压至起脚各阶段的运动力特征，因而达到了认定或否定行走人的目的。至六十年代，发展成我国独特的"步法检验"技术，开始形成有中国特色的足迹检验理论与方法。
所谓我国自己的特色，体现在:①摆脱了传统的"形象痕迹"检验的框子，深入到痕迹形成三要素的作用力的个人特性上。②这项技术是我国自己独创。是马玉林同志和广大痕检工作者对我国足迹检验技术、乃至痕迹学理论与实践的重大贡献，也是我国足迹检验技术发展的重大转折。步法检验技术在六、七十年代迅速在全国普及推广，并在实践中得到进一步发展和完善，即从对连续足迹的检验发展到对单个足迹的检验与分析;从农村发展到城市。
3、全面发展与提高阶段。进入八十年代以来，刑事侦查技术呈现了迅速发展与繁荣的局面。我国足迹检验专家、学者不满足于经验型、手工操作式的足迹检验手段，开始运用人体运动力学、高等数学与计算机技术，研究和解释人体行走与足迹形成的机理，以及影响足迹变化的相关因素，将步法与形象检验相结合，不仅进一步丰富了我国足迹检验理论，也创造了许多新的检验方法和手段。
在此期间，各地研制了一些足迹提取与检验设备、器材。如静电吸附，解决了现场粉尘足迹提取的一大难题，使足迹的提取率和利用率明显提高。各地在办案中因地制宜，综合运用各种检验手段，使过去失去检验条件的现场足迹，重新发挥了证据作用。同时，办案与科研相结合，百花齐放、繁荣科学，基本上形成了我国独特的、以人身识别为目的的足迹检验理论与方法，并在这个领域达到了国际领先水平·
二、我国足迹检验技术的现状及特点
目前，我国足迹检验既有传统的方法，也有许多新的方法和手段。
所谓传统的方法，即从五十年代沿续并不断完善的形象特征检验。加根据现场遗留鞋印判断鞋子的大小、种类，然后同侦查部门提供的嫌疑鞋印比较，进行鞋子的认定或否定。再有根据现场遗留赤足印与嫌疑人赤足印样本比较，可以直接认定作案人。
足迹检验新方法的研究，主要针对犯罪人在作案后将鞋毁弃的情况下，如何利用现场遗留足迹认定犯罪人。专家们努力从步法和反映用力特征的“鞋底常态磨损”上进行了新的探索。
1、足迹定量化检验的探索。最初的尝试是在河南周口地区。从七十年代后期，经过大量的步法统计，运用统计学的理论与方法，求出同一人步法特征变化的阈值，进行不同人的区分。先后设计了“步幅特征级差检验法”、"步幅三角形级差检验法"、“步态特征级差检验法”、"T2检验法"、“隶属度检验法”等。以最简单的"步幅三角形级差检验法"为例，正常行走的足迹中，相邻前后两个普通步为一组(共三枚足迹)，分别画出各足迹中心线并延长，再连结相邻两足迹后边缘与中心线的交点，构成了左右两个步幅三角形。分别测两个三角形底、高及后角，共6项数值，各项数值与嫌疑人比较，如均不超过规定的级差(后角5度，底8公分，高3.5公分)，则判为相同;若一项超过级差，则判为否定。“T2检验法”和，“隶属度检验法”运用了模糊数学理论，计算难度较大，应由侦查人员测量所需数值(井拍成照片)后，提交专业人员上计算机解决。
除了对步幅特征的定量检验外，对步态特征的定量检验研究也有较大进展。在立体足迹中，足底压力不同，表现为石膏模型上的高度差别。在检验时，先测量足迹长、前掌宽及起、落脚角度等4项数值，然后按设定坐标的方法，用河南周口地区研制的“足迹高程测量仪”，测出前掌与趾区的23个点的高程，分别计算出"前掌全坡陡度变差平方和"、"前掌半坡陡度变差平方和"、"拇趾陡度变差平方和"，连同开始测量的4项数值共七项指标，若均不大于规定的阈值则判为接受。此外，还有，“立体足迹立多倍投影测图仪”、"足迹三维数据测量仪"。等，都可以在实践中熟悉掌握和应用。
公安部第二研究所还曾试验了立体赤足印的"光栅检验法"。在质地均匀、透明度，而且两平面精确平行的有机玻璃上，每隔1毫米刻蚀出宽1毫米的黑色不透明刻线，制成"光栅"。把光栅贴在立体赤足印模型上，以平行光从45o角方向射向光栅，就会在上面观察到足迹表面呈现明暗相间的等高线图形。将图形摄入计算机处理，自动测出相关各个切点与重压点，以极坐标方式计算出相关的19个数据，供比较检验。
足迹定量化检验，是足迹检验工作从经验型判别转向科学化判别的重要探索。科学化判别要依赖于数学理论和仪器检验。各地研究的方法，从内容看含有两个部分:一是步法特征的定量化检验;二是足迹中压力分布的定量化检验。从研究动向看也可归纳成两种:一是实用方法研究，如上述的各种定量检验方法，始终以现场足迹和进行比较检验为目标;二是侧重于足迹检验基础理论的研究，如内蒙公安厅和公安大学等单位，通过测力平台和计算机假彩色编码技术，研究足底在行走中压力分布的个人特定性、稳定性及变化规律。这将为足迹人身识别的理论奠定坚实的基础。有了统一、明确的理论，各种各样的检验方法就会完善、统一和全面推广。
足迹检验的仪器化、定量化是发展的必由之路。但目前也存在一些客观的矛盾有待研究解决:其一是绝大多数基层痕检技术人员尚不具备相应的高等数学基础，因而难以更广泛推广使用。其二是现场足迹变化大，影响其形态改变的因素多，现在应用的数理统计方法尚不能完全解决这个难题，所以目前大量地应用于排嫌，而认定结论必须结合其他证据。其三是数理方法尚离不开前期数据的人工测量，这就预伏了不精确的因素，会影响鉴定的准确性。
2、鞋底常态度损特征的检验。所谓"鞋底常态磨损特征"，指人在穿鞋正常行走和运动的过程中，由于较长时间有规律的反复磨耗，而在鞋底形成的磨损形态。它同人的脚型及起落脚规律相对应。脚型和步法是人体稳定而又具个人特征的。所以，同一个人穿用的几双鞋子，其鞋底常态磨损特征应当是相同的。这成为我们解决犯罪人毁弃物证而无法检验的难题打开了一条新路。我国痕检专家、学者从一九八一年开始着手研究这一课题，一九八二年通过模拟实验研究，证实了这一技术理论的可行性。此后，公安部二所在几个地区进行了大量的应用研究，并把磨损检验同足迹中的压力及起落脚检验结合，总结了一套实用的检验方法。一九八六年开始办班推广，一九八七年发表了《利用鞋底磨损特征进行不同种类鞋子检验鉴定》的成果。
常态磨损特征的检验，要在足迹与送检鞋子磨损程度相近的情况下，对趾、拓、弓、踵各区磨损形态及若干特征间的匹配组合关系，进行综合的比较与评断(详见《刑事技术》1982年第6期和公安部二所教材)。它的优点是:①它是鞋底在足与地面作用力下反复磨耗形成的"积累特征"，是作用力特征的形象化，因而易于观察，提高了可见性和可信度。②它既可用于立体足迹检验，也适用于平面足迹检验。
但它也存在一些缺陷:(1)鞋底的磨损毕竟是行走力隔着鞋底作用的结果，不像赤足那样反映细节明显清晰，而是具有一定的模糊性。在脚型相近、步法相近的两个人间，磨损形态也近似，结论要慎重。（2）在受检的两双鞋磨损差别较大时(主要因穿用时间差距大)，单靠磨损特征检验不行，实践中要结合步法特征的压力检验。(3)同一人的平跟鞋与高跟鞋、软底鞋与硬底鞋的磨损会发生一定的差异，检验中要注意。
3。足迹的动力形态检验。这是河北省雄县公安局在原步法检验基础上发展起来的一种检验方法。它主要抓住行走时支撑阶段的七个支撑部位，依先后顺序为:落脚、后跟、脚弓、前掌、趾掌间、趾(主要拇趾)、起脚。先划出七个部位"动力面"(即压力重的部位)的范围。然后以足迹中心线为纵轴（Y），在纵轴前1/3处作纵轴的垂线为横轴(X);然后按平面坐标方法比较七个区动力面的位置、形状、面积及” 动力方向”。所谓”动力方向"，是在每个动力面上找出前后两个最凸点，连结此两点为动力方向。最后再将各动力方向依次连结成曲折的"动力轨迹线"，表示在行走阶段，脚掌力的转移特点，仍可同嫌疑人进行比较。
这种检验方法引入了动力方向和轨迹线的概念，把力的三要素做为整体进行综合分析，因此是有突破的。但动力面的精确划定必需依靠成熟的经验，定量区分的界限难以掌握，同时对送检条件要求较苛刻，因此尚待改进和完善。目前适用于立体足迹。
以上介绍的几种检验技术，都是近十几年来根据实践斗争需要摸索和发展起来的。它们各自都有自已的长处，井对原来的手段有所突破，但也都不是全能的，无论在理论还是实践上都正待进一步提高。
三、足迹检验技术今后的发展方向
我国对足迹检验技术的研究，目前处于空前繁荣的局面。为了使本学科尽快实现理论与实践统一下的规范化、科学化，今后重点研究发展的方向应当是:
1、下大力量加强本学科应用理论的研究。目前，本学科借用相关的基础理论较多，但距彻底解释足迹检验中的实际问题尚差较远。目前的理论研究，应当借助于相关学科成熟的理论和手段，通过大量测试与统计，论证人体行走脚底压力分布的特定性与稳定性，提出产生变异的客观原因及一般规律。这样才真正建立起足迹检验完整、科学的理论基础。
2、足迹认定人身的检验技术，应当在特征的确认上向仪器化、定量化及规范化发展，尽量排除对个人经验的依赖。这项研究的难度是较大的，需要警内外科技人员的协作，目前已取得了较大进展。
3、提倡和推广足迹综合应用经验。足迹中蕴藏的有益信息很多，从人体气味，到形象
特征、步法特征、磨损特征、动力形态特征以及微量遗留物质；进行多途径、多学科和多手段的相互配合，充分扩展足迹在侦查工作中的作用。要实现综合利用的目标，应当设计从现场到鉴定的一整套完善的足迹检验标准化工作程序，作为规范实施。同时要相应地研究或改进一些足迹特征的提取与保存方法，以适应多种检验手段的相互协调配合。
（兰绍江）
(本文原载于天津《警察学研究》１９９４年第２期 作者:天津公安学校校长)
METROLOGY LAW OF THE PEOPLE'S REPUBLIC OF CHINA
The Standing Committee of the National People's Congress
METROLOGY LAW OF THE PEOPLE'S REPUBLIC OF CHINA
(Adopted at the 12th Meeting of the Standing Committee of the
Sixth National People's Congress, promulgated by Order No. 28 of the
President of the People's Republic of China on September 6, 1985, and
effective as of July 1, 1986)
Contents
Chapter I General Provisions
Chapter II Primary Standard Instruments of Measurement, Standard
Instruments of Measurement and Metrological Verification
Chapter III Administrative Control of Measuring Instruments
Chapter IV Metrological Supervision
Chapter V Legal Liability
Chapter VI Supplementary Provisions
Chapter I General Provisions
Article 1
This Law is formulated to strengthen the metrological supervision and
administration, to ensure the uniformity of the national system of units
of measurement and the accuracy and reliability of the values of
quantities, so as to contribute to the development of production, trade
and science and technology, to meet the needs of socialist modernization
and to safeguard the interests of the state and the people.
Article 2
Within the territory of the People's Republic of China, this Law must be
abided by in establishing national primary standards of measurement and
standards of measurement, in conducting metrological verification, and in
the manufacture, repair, sale or use of measuring instruments.
Article 3
The State shall adopt the International System of Units (SI).
The International System of Units and other units of measurement adopted
by the State shall be the national legal units of measurement. The names
and symbols of the national legal units of measurement shall be
promulgated by the State Council. Non-national legal units of measurement
shall be abrogated. Measures for the abrogation shall be stipulated by the
State Council.
Article 4
The metrological administrative department of the State Council shall
exercise unified supervision over and administration of metrological work
throughout the country. The metrological administrative departments of the
local people's governments at and above the county level shall exercise
supervision over and administration of metrological work within their
respective administrative areas.
Chapter II Primary Standards of Measurement, Standards of Measure- ment and Metrological Verification
Article 5
The metrological administrative department of the State Council shall be
responsible for establishing all kinds of primary standards of
measurement, which shall serve as the ultimate basis for unifying the
values of quantities of the country.
Article 6
The metrological administrative departments of the local people's
governments at or above the county level may, according to the needs of
their respective areas, establish public standards of measurement, which
shall be put into use after being checked and found to be qualified by the
metrological administrative department of the people's government at the
next higher level.
Article 7
The competent department concerned of the State Council and the competent
department concerned of the people's governments of the provinces,
autonomous regions, and municipalities directly under the Central
Government may, in light of their own specific needs, establish standards
of measurement for their own use. The ultimate standard of measurement of
each kind shall be put into use after being checked and found to be
qualified by the metrological administrative authorities of the people's
government at the corresponding level.
Article 8
Enterprises or institutions may, according to their needs, establish
standards of measurement for their own use. The ultimate standard of
measurement of each kind shall be put into use after being checked and
found to be qualified by the metrological administrative department of the
people's government concerned.
Article 9
The metrological administrative departments of the people's governments at
or above the county level shall make compulsory verification of the public
standards of measurement, the ultimate standards of measurement used in
the departments, enterprises and institutions as well as the working
measuring instruments used in settling trade accounts, safety protection,
medical and health work, or environmental monitoring that are listed in
the compulsory verification catalogue. Those measuring instruments which
have not been submitted for verification as required and those which have
been checked and found to be unqualified shall not be used. The catalogue
of the working measuring instruments subject to compulsory verification
and the measures for the administration of such instruments shall be
stipulated by the State Council.
Standards of measurement and working measuring instruments other than
those referred to in the preceding paragraph shall be verified at regular
intervals by the users themselves or by the metrological verification
institutions. The metrological administrative departments of the people's
governments at or above the county level shall supervise and inspect such
verification.
Article 10
Metrological verification shall be conducted according to the National
Metrological Verification System. The National Metrological Verification
System shall be worked out by the metrological administrative department
of the State Council. Metrological verification must be carried out in
accordance with the regulations governing metrological verification. The
national metrological verification regulations shall be formulated by the
metrological administrative department of the State Council. In the case
of certain instruments that are not covered in the national metrological
verification regulations, the competent departments of the State Council
and the metrological administrative departments of the people's
governments of provinces, autonomous regions, and municipalities directly
under the Central Government shall respectively formulate departmental and
local verification regulations. Such verification regulations shall be
submitted to the metrological administrative department of the State
Council for the record.
Article 11
Metrological verification shall, according to the principle of economy and
rationality, be carried out on the spot or in the vicinity.
Chapter III Administrative Control of Measuring Instruments
Article 12
An enterprise or institution which is to engage in manufacturing or
repairing measuring instruments must have facilities, personnel and
verification appliances appropriate to the measuring instruments it is to
manufacture or repair and, after being checked and considered as qualified
by the metrological administrative department of the people's government
at or above the county level, obtain a Licence for Manufacturing Measuring
Instruments or a License for Repairing Measuring Instruments.
The administrative departments for industry and commerce shall not issue a
business licence to an enterprise engaged in manufacturing or repairing
measuring instruments which has not obtained a Licence for Manufacturing
Measuring Instruments or a Licence for Repairing Measuring Instruments.
Article 13
When an enterprise or institution manufacturing measuring instruments
undertakes to manufacture new types of measuring instruments which it has
not previously manufactured, such measuring instruments may be put into
production only after the metrological performance of the sample products
has been checked and found to be qualified by the metrological
administrative department of a people's government at or above the
provincial level.
Article 14
Without the approval of the metrological administrative department of the
State Council, measuring instruments with non-legal units of measurement
which have been abrogated by the State Council, and other measuring
instruments which are banned by the State Council, shall not be
manufactured, sold or imported.
Article 15
An enterprise or institution engaged in manufacturing or repairing
measuring instruments must verify the measuring instruments it has
manufactured or repaired, guarantee the metrological performance of the
products and issue certificates of inspection for the qualified products.
The metrological administrative department of the people's governments at
or above the county level shall supervise and inspect the quality of the
measuring instruments manufactured or repaired.
Article 16
Measuring instruments imported from abroad may be sold only after having
been verified and found to be up to standard by the metrological
administrative department of the people's government at or above the
provincial level.
Article 17
When using measuring instruments, no person shall be allowed to impair
their accuracy, thereby prejudicing the interests of the State and
consumers.
Article 18
Self-employed workers or merchants may manufacture or repair simple
measuring instruments.
Any self-employed worker or merchant who is to engage in manufacturing or
repairing measuring instruments may apply for a business licence from the
administrative department for industry and commerce provided he has been
tested and found to be qualified by the metrological administrative
department of a people's government at the county level, and issued a
Licence for Manufacturing Measuring Instruments or a Licence for Repairing
Measuring Instruments.
The types of measuring instruments which can be manufactured or repaired
by self-employed workers or merchants shall be determined by the
metrological administrative department of the State Council, which shall
also adopt measures for their control.
Chapter IV Metrological Supervision
Article 19
The metrological administrative department of the people's governments at
or above the county level may, according to their needs, appoint
metrological supervisors. The measures for the administration of the
metrological supervisors shall be formulated by the metrological
administrative department of the State Council.
Article 20
The metrological administrative department of the people's governments at
or above the county level may, according to their needs, set up
metrological verification organs or authorize the metrological
verification institutions of other establishments to carry out compulsory
verification and other verification and testing tasks. The personnel
carrying out the tasks of verification and testing mentioned in the
preceding paragraph must be tested for their qualifications.
Article 21
Any dispute over the accuracy of measuring instruments shall be handled in
accordance with the data provided after verification with the national
primary standards of measurement or public standards of measurement.
Article 22
A product quality inspection agency which is to provide notarial data on
the quality of products for society must be checked for its capability and
reliability of metrological verification and testing by the metrological
administrative department of a people's government at or above the
provincial level.
Chapter V Legal Liability
Article 23
Whoever without a Licence for Manufactured Measuring Instruments or a
Licence for Repairing Measuring Instruments manufactures or repairs
measuring instruments shall be ordered to stop his production or business
operations. His unlawful income shall be confiscated and a fine may
concurrently be imposed.
Article 24
Whoever manufactures or sells a new type of measuring instrument which has
not been checked and found to be qualified shall be ordered to stop the
manufacture or sale of that new product. His unlawful income shall be
confiscated and he may concurrently be punished by a fine.
Article 25
Whoever manufactures, repairs or sells unqualified measuring instruments
shall have his unlawful income confiscated and a fine may concurrently be
imposed.
Article 26
Whoever uses measuring instruments subject to compulsory verification
without having filed an application for verification as required or
continues to use measuring instruments which have been checked but found
to be unqualified shall be ordered to stop the use and may concurrectly be
punished by a fine.
Article 27
Whoever uses unqualified measuring instruments or impairs the accuracy of
measuring instruments, thus causing losses to the State and consumers,
shall be ordered to make compensation for the losses and shall have his
measuring instruments and unlawful income confiscated and may concurrently
be punished by a fine.
Article 28
Whoever manufactures, sells or uses measuring instruments for the purpose
of deceiving consumers shall have his measuring instruments and unlawful
income confiscated and may concurrently be punished by a fine. If the
circumstances are serious, the individual or the person in the unit who is
directly responsible shall be investigated for his criminal responsibility
according to the crimes of swindling or speculation.
Article 29
When any individual or unit, in violation of the provisions of this Law,
manufactures, repairs or sells unqualified measuring instruments leading
to people's injury or death or causing major property losses, the
individual or the person in the unit who is directly responsible shall be
investigated for his criminal responsibility by reference to the
provisions of Article 187 of the Criminal Law.
Article 30
A metrological supervisor who transgresses the law and neglects his duty,
where the circumstances are serious, shall be investigated for criminal
responsibility pursuant to the relevant provisions of the Criminal Law. If
the circumstances are minor, he shall be given an administrative sanction.
Article 31
The administrative sanction provided for in this Law shall be determined
by the metrological administrative department of a people's government at
or above the county level. The administrative sanction provided for in
Article 27 of this Law may also be determined by the administrative
departments for industry and commerce.
Article 32
A party who refuses to accept the decision of the administrative sanction
may, within 15 days after receipt of the notification of the decision,
file suit in a people's court. If within that time limit the party does
not file suit or comply with the penalty of paying a fine and having his
unlawful income confiscated, the administrative authorities which have
made the decision of the administrative sanction may request the people's
court for compulsory execution.
Chapter VI Supplementary Provisions
Article 33
Measures for the administration of and supervision over metrological work
in the Chinese People's Liberation Army and in units under the
jurisdiction of the Commission on Science, Technology and Industry for
National Defence shall be formulated separately by the State Council and
the Central Military Commission in accordance with this Law.
Article 34
The metrological administrative department of the State Council shall, in
accordance with this Law, formulate rules for its implementation, which
shall go into effect after being submitted to and approved by the State
Council.
Article 35
This Law shall go into effect on July 1, 1986.
Important Notice:
This English document is coming from "LAWS AND REGULATIONS OF THE
PEOPLE'S REPUBLIC OF CHINA GOVERNING FOREIGN-RELATED MATTERS" (1991.7)
which is compiled by the Brueau of Legislative Affairs of the State
Council of the People's Republic of China, and is published by the China
Legal System Publishing House.
In case of discrepancy, the original version in Chinese shall prevail.