It is also important to be aware of the fact, that in case if you are going to contrast both sides of the argument, you should better start with the side of the argument, you do not agree with. It is considered to be more natural in English, in addition, you essay introduction will develop in a logical order toward the thesis statement.

Step three: writing the thesis statement
After you have developed your essay introduction, it is time to write your thesis statement. This is considered to be the last sentence in you first paragraph. In addition, it is also the most important sentence in the entire essay, because it usually plays two roles:
• It provides a direct answer to the question of your essay;
• The reader gets to know your opinion.

Taking into consideration the introduction, provided as an example, here what the thesis statement can look like:

No police officer should ever carry a gun with him.

The thesis statement here is rather simple and it is direct; it provides the answer to the question of the essay, as well as it tells the reader exactly what the author’s opinion is.
It should also be mentioned without a sign of an exaggeration, that thesis statement is the most important sentence of the essay. Moreover, in case if the reader has some difficulty understanding the essay, he/she usually returns to the thesis statement in order to get reminded what the essay is about. There is no need to say that a bad thesis statement usually results in a bad essay.

 Step four: putting it all together
Here is the complete introduction to out essay:

Many communities debate whether or not police officers should carry guns. There are situations, when guns help to protect the police officer, as well as the public; therefore, from the other point of view, guns can result in serious injuries and even death. No police officer should ever carry a gun with him.

In our first sentence the introduction is begun with a general statement about the topic of the essay. After that, in the second sentence, two possible sides of the argument are contrasted. And, finally, the last sentence is called the thesis statement, because it is it, which provides an answer to the question of the essay, as well as gives the author’s opinion.