Each company has numerous video cameras for Ranger use and recently each headquarters office was issued a digital camera. In recent years great strides have been made in the use of DNA for identification purposes. There have been several high profile trials where DNA evidence has been introduced. After collecting evidence, Rangers can send samples to the Crime Laboratory Service in Austin or to a local field lab for DNA analysis. The study of the characteristics of firearms and cartridges is called ballistics.
Investigators use ballistics to match evidence with suspects and weapons used in crimes.
Rangers and forensic investigators examine patterns of blood at crime scenes to determine important facts about the crime. The shape and characteristics of blood stains and spatters reveals their direction and velocity. This can reveal the type of weapon used, the direction of the blow, and where the victim was located when attacked. Although Rangers do not conduct polygraph tests themselves, they have access to the process through the DPS Polygraph service. The so-called lie detector tests are used in interviewing witnesses, suspects, and victims.