What can me done in my case when in the investigation they only called of witness of the other part?

It is common for assault charges in Texas to be brought to trial with just one witness, that is the alleged injured party. The fact that there is only one witness will not keep the prosecutor from pressing forward with the charges. A typical assault charge is a Class A misdemeanor punishable by up to a year in jail. Your attorney will have an opportunity to cross examine the alleged victim or any other witness. You will also be able to subpoena witnesses on your behalf and if there are no other witnesses then your attorney will focus on discrediting the witness. For more information about the charges generally, you can click here: Assault Defense in Texas. You can also consider subpoenaing records from the school through a subpoena duces tecum.