TEXAS CODE CHAP. 14
Art. 14.01.    OFFENSE WITHIN VIEW. (a) A
peace officer or any other person, may, without a warrant, arrest an offender when the offense is committed in his presence or within his view, if the offense is one classed as a felony or as an offense against the public peace.
Sounds like the 2 Good Samaritans witnessed a felony and tried to arrest the miscreant which is permissible under Texas law.
Actually, the real learning lesson from this incident is to not stick around after shooting a bad guy.
Last edited by WT; 01-12-2013 at 12:18..