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Terrain analysis: From corrections to patrol

Several months ago I made the transition from custody sergeant to patrol sergeant. One day I was working the largest (with nearly 800 sworn employees) jail in the Los Angeles Sheriff’s Department, the next I was working one of our smallest patrol stations (with fewer than 50). Needless to say, the resources available to me changed dramatically.

I went from supervising thirty deputies on one floor who were overseeing approximately 800 inmates to leading six to ten deputies patrolling 8.5 square miles in an area home to nearly 90,000 people. Those thirty deputies I supervised at Men’s Central Jail were also only a fraction of the personnel assigned to work each shift. So backup was only a stone’s throw away. Now, if we need help, it is coming from other Sheriff’s stations and local PD’s. Doing more with less is the nature of patrol. But there is another distinct disadvantage. On many different levels, when you work patrol you always play your games as the road team. It is just the opposite in a jail.


Perhaps the biggest advantage to working inside a jail, however, is that you own the real estate. Unlike patrol, you are always the home team. You know the terrain and all of its nuances better than your opponent. You control the points of ingress and egress. You know where the choke points are. Your staging areas and command posts are normally predetermined. This is a tremendous tactical advantage and one that is often must be addressed anew each time a major incident occurs in the field.

One of the most important things a leader needs to do before attempting to deal with a tactical incident is conduct a terrain analysis. Military leaders have been aware of this for thousands of years. At the beginning of his thesis The Art of War, Sun Tzu identified five factors that must be studied: two concerned leadership, a general’s knowledge and his ability to maintain unity of command; one dealt with logistics; and two (Heaven and Earth) dealt with terrain.(1) The effective use and appreciation of terrain analysis can even be found in the Bible.(2) The terrain analysis lessons of centuries were reduced by military thinkers to a five part process known by the acronym KOCOA. The KOCOA analysis considers: key terrain, also referred to as critical terrain; observation and fields of fire; cover and concealment; obstacles; and avenues of approach and escape.

In all jail incidents, with the possible exception of a hostage event or Attica-type complete takeover of a facility, correction’s staff should have control over three of these five points. A fourth point, cover and concealment, should at worst be a draw. The only area where inmates may have a temporary terrain advantage is through the erection of some kind of barricade creating an obstacle that must be breached. Having an obvious terrain advantage does not necessarily make handling a jail disturbance easy. Some of the barricades inmates can erect are quite elaborate and take time to defeat. They also can occur on a scale and with a number of adversaries rarely ever seen in the field. Still, correctional facilities are known terrain. Corrections staff work there every day. They also know the players, both through casual day to day contact and more detailed access to their records.

A terrain analysis in the field is not only more difficult, but it is also often done on the fly, under stress and with very little known about the opponent or the location. While it is true that we all have problem residences, complexes and neighborhoods, have all officers been to all of the nooks and crannies in these places at all times of the day or night? New supervisors on small PDs usually take the local institutional memory of the city with them to the next rank. Larger departments don’t often have this luxury. New field supervisors find themselves working stations or units that they never worked as an officer. Or it was so many years ago that a great deal has changed.

When I first arrived at my new station I knew nothing about the area. I deferred to my senior people when we entered territory that was familiar to them. It was in our debriefings where I began to ask questions and make suggestions. Most of us learn our KOCOA knowledge of a location through repeated experience. Armed with the knowledge of this helpful acronym up front your situational awareness will increase and your reaction time (OODA loop) will shorten. Try to do a KOCOA analysis each time you respond to a call.

Identify the Key Terrain – Key terrain is any place or area whose control gives you a significant advantage. This may not necessarily be the high ground. It could be the narrow street in front of a location or the gated entrance to an apartment complex. Are there obvious choke points? Is there some place whose control will be decisive? In a jail it is not the jail row or module itself that is the key terrain: it is most often the sally port or common area in front of the row or dorm. The loss of this area increases the size of your problem exponentially. If your partners are involved in a fight inside a courtyard beyond a locked security screen, the key terrain feature is frustratingly obvious.

Remember, key terrain does not necessarily need to be occupied only controlled. Jail modules and dorms can be locked down. How do you achieve the functional equivalent at with the key terrain at a location you are responding to in the field? There is a reason why identifying key terrain features is the first component of your terrain analysis. Knowing it and controlling it may be the difference between a successful or tragic outcome to your operation.

Observation and Fields of Fire – These two concepts are so closely connected that they are considered together, but too often law enforcement tends to think of them separately. There may be many electronic marvels available to us today to listen in and observe bad guys, but to the average patrolman it is still eyes on the target. Get somewhere that you can see. Ideally, this should be at a surreptitious location away from the bad guy’s view. Identify your key terrain before you move.

Seeing the location is critical but you must also take into consideration fields of fire. A field of fire is defined as, “The characteristics of the weapon and how it is deployed.”(3) This takes into consideration the area the weapon is capable of controlling and how it is used. Shotguns with conventional buckshot ammunition have limited range. Handguns are better, but most cops aren’t that good with them in battle at distances greater than twenty yards. Long rifles are the best alternative for good stand off distance, but not all personnel are equipped with them and can those who do have them arrive quickly enough for them to be of immediate use? The terrain you are working with will change the field of fire. A weapon is of no value if your view from the suspect is obscured by trees and a weapon located on a rooftop has a greater field of fire than one on the ground. All weapons have their pros and cons. Handguns are the most portable but are not as accurate at long range as rifles, but these are awkward to carry.

Be careful not to confuse fields of fire with sectors of fire. While fields of fire are based on the capability of the weapon and its placement, a sector of fire is an assignment. The most common configuration in a felony traffic stop is four patrol officers each manning one of the four doors of the first two vehicles immediately behind the suspect. If the suspect begins to shoot and then runs laterally from his vehicle, the officers on the opposite side from where the suspect is running must be careful not to continue turning their body and firing at him. The sector of fire for each officer is limited and its integrity must be maintained to avoid a potential tragedy.

Those working in a jail have a tremendous advantage when it comes to observation and fields of fire. Observation posts can be predetermined. Fire ports for the introduction of ordnance are often built that allow the introduction of less lethal and, if necessary lethal munitions. Some facilities even establish range cards. In a jail, a range card is often some object or objects set at predetermined distances that permit a quick assessment of what the field of fire is for a given type of munition. No Smoking signs set up at twenty meter intervals down a long hallway or in a recreation yard help to estimate range and ensure that a round is employed properly when called upon. This is another advantage of playing all your games at home.

Cover and Concealment – When working patrol it seems that countless terrain features provide concealment, but painfully few also offer cover. Concealment does little more than hide you from view. There is obvious value in this until bullets start to fly.

When you are behind cover you are protected from fire and its effects. The more powerful the weapon used against you the less and less cover is available to you. Fire hydrants are good, but they aren’t very big. Mail boxes are larger, but don’t do very well against larger caliber handgun ammo. Wood framed houses make terrible cover. Bullets pass right through them. One of the most misleading places for cover is a patrol car. The engine block is the only thing that provides real cover. Unless your department has reinforced the doors of your vehicle, almost all ammunition will punch right through them. Also, some objects may appear tempting as cover, but take into consideration what they are designed for. Some things go boom when they are struck by bullets and these objects are easier to hit than you are.

Jails again have a tremendous advantage. First, it is an extremely bad day if an inmate has a gun inside a jail. This is not unprecedented, of course, but it is rare. Should a gun battle take place in a jail almost every wall is impervious to small arms and rifle fire due to their concrete and steel construction. The biggest problem jail personnel face when employing lethal force is from ricochets.

Obstacles – Obstacles are everywhere. They must be contended with both inside jails and on the streets. But obstacles can work for you as well as against you. Sometimes they are so severe, like deep drainage channels or high fences with razor wire, that they are barriers. If you must circumvent these barriers, this is bad. But if you can force your opponent up against them this is good. Obstacles such as traffic may exist only during certain hours of the day. Others like a moving freight train are temporary. What is an obstacle to a car may not be an obstacle to a bicycle or a pedestrian.

Also, be careful that you do not create your own obstacles. Just how many patrol cars to you need at the termination of a pursuit or in front of a location on a narrow street? If you have too many, you get in the way of each other. This can impact your ability to get or away or just get to something that may be a greater priority. This leads to the final part of our KOCOA analysis.

Avenues of Approach and Avenues of Escape – You need a way in and you need a way out. These routes of approach and retreat are much easier to impact in custody, especially since most responses are made on foot. But when you have to arrive in vehicles many other things must be considered. How wide is the street? Will you need fire on scene? If so, have you parked so they won’t block you in?

Avenues of approach and retreat are often choke points that become key terrain features in a patrol setting and they must be evaluated at every call. The only time I ever saw this become an issue in a jail was when one facility decided that all responses to emergencies would be via elevator and not staircase. This created an unnecessary choke point in emergency responses. For the most part home teams know how to use their own terrain to maximum advantage.

Conclusion – Road teams always face more adversity than home teams. The crowd is hostile and the landscape is unfamiliar. It may seem odd to those working patrol that any one can ever become comfortable working in a jail, but this is the familiar home field to many. Knowing the playing field has distinct advantages for those working in corrections. Doing a conscious KOCOA analysis is a way to help level the playing field against the adversaries you encounter on the streets.(4)

1) Sun Tzu, The Art of War, Ralph D. Sawyer translation, Westview Press Inc., 1994, pg. 167.
2) For example, consider Joshua’s use of terrain at the Battle of Ai in chapter 8 of the Book of Joshua; Ehud’s seizure of “the fords of the Jordan” and subsequent defeat of Moab in the third Chapter of the Book of Judges; Deborah’s appreciation of the weakness of Jabin’s iron chariots on the soft ground near the River Kishon and their subsequent defeat in chapter four of the Book of Judges; and Jonathan’s defeat of a superior force in the Michmash campaign in 1 Samuel 14, to name but a few.
3) Heal, Sid, An Illustrated Guide to Tactical Diagramming, Lantern Books, New York, NY, 2006, pg. 14.
4) For additional resources see: Heal, Sid, “Terrain Analysis,” The Tactical Edge, Summer 2000, p. 73 and The Los Angeles Tactical Science Course, Terrain Analysis, presented February 2008 at the Glendale Police Department.

Lieutenant John J. Stanley, M.A., is a twenty-seven year veteran of the Los Angeles Sheriff’s Department. He has worked a variety of assignments including, custody, patrol, training and administrative support. He is considered an expert on less lethal weapons and tactics. He provided corrections scenarios for the Institute for Non-Lethal Defense Technologies Applied Research Laboratory at Penn State University and contributed to its on-line Less Lethal Weapons class. John spent over a decade at LASD’s Custody Training Unit teaching classes such as Tactical Communications, Jail Intelligence Gathering, Tactical Weapons, Squad Tactics and Cell Extractions. John also was the lead instructor for LASD’s Custody Incident Command School (CICS) a class designed for sergeants and lieutenants and the Executive Incident Command School (EICS) for captains and above. He is a member of the California Tactical Officers Association and has published almost forty articles on law enforcement tactics and legal history.