Sure you can - but you have to do it the legal way - here's NC's law on it.
15A-404. Detention of offenders by private persons.
(a) No Arrest; Detention Permitted. – No private person may arrest another person except as provided in G.S. 15A-405. A private person may detain another person as provided in this section.
(b) When Detention Permitted. – A private person may detain another person when he has probable cause to believe that the person detained has committed in his presence:
- (1) A felony,
- (2) A breach of the peace,
- (3) A crime involving physical injury to another person, or
- (4) A crime involving theft or destruction of property.
(c) Manner of Detention. –
The detention must be in a reasonable manner considering the offense involved and the circumstances of the detention.
(d) Period of Detention. – The detention may be no longer than the time required for the earliest of the following:
- (1) The determination that no offense has been committed.
- (2) Surrender of the person detained to a law-enforcement officer as provided in subsection (e).
(e) Surrender to Officer. – A private person who detains another must immediately notify a law-enforcement officer and must, unless he releases the person earlier as required by subsection (d), surrender the person detained to the law-enforcement officer. (1973, c. 1286, s.1.)
So you tell the shoplifter they are being detained and attempt to do so - if they resist, you get to resist their resistance. You can't cut their achilles or anything... but if you have to restrain somebody that's trying to push past you, you gotta do what you gotta do.