Watch Your Step: The Potential Use of Smart Concrete in Law Enforcement

By Kathryn Threatt

In his podcast, The Justice Tech Download, Jason Tashea envisions a new and smart use for concrete: to collect data to identify perpetrators via gait analysis.[1]

Imagine. As you walk along your city’s sidewalks the sensors within its concrete track your steps and your gait. You pause just before someone bumps into you. That someone just rushed out of a convenience store. You notice a few characteristics about them as they pass by: hair color, height in comparison to your own, shade of clothing, and race/ethnicity. Your attention then turns to the convenience store owner who runs out of the store screaming, “Thief!” The alleged thief then sprints down the street and disappears before anyone stops them. The police take your statement and gather data from this smart sidewalk when they arrive.

In Jason Tashea’s vision, the police will summon individuals that fit the data gathered or the description given at the crime scene.[2] Once in police custody, the officer will then ask these individuals to walk across a mat that tracks their biometric data: footprints and gait.[3] This mat is connected to a monitor that the officer is watching.[4] If the footprints on the screen–taken from the data gathered from the smart sidewalk–match the footprints on the mat the screen turns green.[5] A green screen means the officer caught the alleged thief.[6]

As cities globally begin to move toward the smart city concept the use of smart concrete in perpetrator identification might lead to dire consequences. Because of the risk factors associated with use, it will be critical that legislators regulate how this technology is implemented for gait analysis purposes.


A Brief Background: Key Concepts

A smart city is a city that uses interconnected devices and wireless technology to increase the city’s efficiency via data collection and exchange.[7] Advocates of these tech-integrated municipalities argue that the many technologies the cities employ like traffic lights that adjust their internal timing to accommodate traffic flow will increase efficiency, save money, and produce safer cities.[8] “Smart concrete” or “smart pavement” is another example of a technology that a smart city might implement for these primary purposes. Smart concrete uses internal sensors to monitor the current or imminent presence of cracks and damages.[9] While smart concrete’s development spans more than two decades the technology is not yet commercially available.[10] Proponents of the technology argue that outside of use for efficient management and updates to critical infrastructure, smart concrete can also be used for crowd management, roadway de-icing, and crash support.[11] According to Jason Tashea, another use for smart concrete is in gait analysis.[12] Gait analysis is the study of one’s gait using CCTV cameras and footprints found at the crime scene to identify a suspect.[13] The idea is that the sensors in the smart concrete would collect this footprint data and provide law enforcement with the ability to match this footprint with the live footprint gathered via the mat during a lineup.[14]


Should Smart Concrete be used in Gait Analysis?

Using smart concrete for gait analysis has significant benefits. First, the technology promotes overall increased safety for communities.[15] The technology puts potential perpetrators on notice that their movements are being monitored in this way. The long-term hope would be that this notice serves as a deterrent to criminal activity. Second, in the long-term, the technology is cost-effective as the gait analysis use is a secondary benefit. If the concrete is already in place in the city there would likely be no increased financial costs to gather the data for suspect identification; the main costs would be for the mats and monitors to match the footprints in the police stations. Third, the use of smart concrete in conjunction with other gait analysis tools like CCTV video and physical footprint data at the scene will likely improve the rate of accuracy in perpetrator identification.

However, there are also downsides. First, the general collection of this data is a form of surveillance and surveilled cities disproportionately impact vulnerable populations.[16] This disproportional impact arguably leads to increased policing.[17] Secondly, there are privacy concerns because individuals would most likely not opt into their data being collected and subsequently used in this way.[18] Third, the use of one’s biometric data–in this instance collecting data on one’s footprint–presents a potential violation of the Fourth Amendment. The Fourth Amendment guarantees that “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized”[19] Because one’s gait is biometric data it is personal to the individual. Without their consent to this taking, law enforcement’s use of the data might be seen as an “unreasonable search and seizure”.

Weighing the costs and benefits, smart concrete has the potential to provide invaluable information to increase safety in cities and thus should be used by law enforcement in gait analysis with restrictions. State and federal legislators are in the prime position to think through and propose legislation that protects citizen’s rights and decreases adverse impacts of law enforcement use before the technology’s implementation. Therefore, if smart concrete is used by law enforcement–and it should be–for gait analysis purposes, the technology should only be used in conjunction with other gait analysis tools like CCTV footage, physical footprints, and if possible, eyewitness testimony. This tandem use potentially lowers the risks of over-policing vulnerable communities and provides another checkpoint or backstop to confirm identity. Furthermore, with the notice element inherent in the technology and the current use of CCTV footage and physical footprints to collect this type of data extending the collection to smart concrete arguably would not violate one’s Fourth Amendment rights. Smart concrete is an invaluable resource that if used properly can significantly benefit our society.


* This blog has been adapted from an emerging technology presentation for National Security & New Tech.








[1] Jason Tashea, 40 Futures: Perp Walk, the justice tech download,

[2] Id.

[3] Id.

[4] Id.

[5] Id.

[6] Jason Tashea, supra note 1.

[7] Sharon Shea, Smart City, Techtarget: IoT Agenda,,government%20services%20and%20citizen%20welfare; see also What Is A Smart City? ­– Definition and Examples, TWI,

[8] See, e.g., What Is A Smart City? ­– Definition and Examples, TWI, (describing how traffic lights used in smart cities can reduce congestion by adjusting the length of the lights based on the flow of traffic).

[9] Antonella D’Alessandro et al, Towards smart concrete for smart cities: Recent results and future application of strain-sensing nanocomposites, J. of Smart Cities 3, 4 (2015).

[10] Science of Innovation, youtube (2020),; ECT Team, Smart Concrete, Purdue univ. (2007), 2,yet%20available%20in%20the%20market.&text=1.

[11] D’Alessandro, supra note 9, at 2, 10 (2015); What is Smart Pavement, Youtube (2017),

[12] Tashea, supra note 1.

[13] Ashish Badiye, Forensic Gait Analysis: Introduction, (Nov. 7, 2022)

[14] Tashea, supra note 1.

[15] See, e.g., Brad Smith, Why Smart Cities Threaten Citizens’ Right to Privacy, Urbanet (Nov. 18, 2020),,means%20to%20protect%20one’s%20privacy (arguing that smart cities generally tend to decrease crime).

[16] Robert Muggah, ‘Smart’ Cities Are Surveilled Cities, ForeignPolicy (Apr. 17, 2021, 6:00 AM),; see Ben Green and Greg Walton, Smile, Your City Is Watching You, NY Times: Opinion | The Privacy Project (June 27, 2019),

[17] Muggah, supra note 16.

[18] Brad Smith, supra note 15.

[19] U.S. Const. amend. IV.


Image Source: