1.   In response to taxi robberies, Mexico City police began operations to capture unlicensed taxis.

2.   No figures are kept on the number of taxi robberies.

3.   On Saturday, del Villar obtained new arrest warrants against the five suspects, but this time in relation to other taxi robberies.

4.   The killing comes several years after a spate of taxi robberies and shootings prompted the taxi industry to put new safety precautions in yellow cabs.

5.   The taxi robberies virtually halted by late February.

6.   New security measures are to be introduced following a recent wave of taxi robberies and two high-profile cases involving Americans in recent days.

7.   Prosecutors contend alleged triggerman Gonzalez and the four other men killed Zarate in a taxi robbery.