Texas County and District Attorney Association
Exigent circumstances
Probable cause along with exigent circumstances may justify a search or entry without a warrant.2 This is also known as the “emergency doctrine.” Article 14.05 of the Code of Criminal Procedure also includes a provision that authorizes officers to enter homes without a warrant with exigent circumstances.3 Exigent circumstances cases typically involve:
• protection of life (first aid; extracting children who appear in danger; protecting an undercover officer or informer; or making a protective sweep);4
• protection of property (such as extinguishing a fire or stopping a burglary);5
• preventing destruction of evidence;6 and
• pursuing a fleeing felon (“hot pursuit”

.7
Remember that exigent circumstances may justify the initial entry in the house, but because the purpose of the exception is to aid someone in distress or to secure safety, once the crisis is contained, further searching is not permitted.8 A warrant or another exception may authorize continued searching of the premises, however, and officers can secure the scene for the time it takes to get a warrant. The exigent circumstances doctrine also does not include a general murder scene exception that would authorize unlimited search of the premises, although officers may enter a home to provide immediate aid or to search for other victims or a killer.9
Because the exigent circumstances exception is typically applied in cases where officers need to make a warrantless entry rather than a warrantless stop or detention, the exigent circumstances exception typically will not be relevant in a traffic stop. It may become relevant, however, if a driver flees police, abandons his vehicle, and runs into a house or building.
http://www.tdcaa.com/node/7759