They believe Esequiel Villareal, 39, may be heading to Mexico in a Nissan Maxima with Texas license plates 909-JKR.

The victim, 35-year-old Bendicata Gonzalez, was shot several times in front of her 15-year-old son Thursday morning.

Family members say she had moved to a new apartment complex to hide from Villareal, but he found her by following her home from the son's school.

Villareal was released from prison in May 2005 for an unrelated murder charge.

Anyone with information on the whereabouts of Esequiel Villareal is urged to contact the HPD Homicide Division at 713-308-3600 or Crime Stoppers at 713-222-TIPS.