July 3, 1878; San Patricio, Lincoln County, New Mexico Territory---Believing the Regulators and Alex McSween will be back in San Patricio by now, Deputy Jose Chavez y Baca organizes a posse of about a dozen men to accompany him there and attempt to "arrest" them. They leave Lincoln a short time before dawn and head south to San Pat. What the posse doesn't know is that the Regulators are expecting another attack. Before the posse even reaches San Pat, the Regulators climb to the roofs of the buildings scattered around the small village's plaza. They lay behind the adobe breastworks that rise above the roofs and carve portholes in them for their rifles, thereby keeping them out of sight, but at the same time giving them a clear view of anyone approaching the town.
Just as the sun is rising, the Baca posse rides into San Pat. At first, everything is quiet. Then, almost at once, a fusillade of lead is discharged from the hidden Regulators' rifles. The posse scatters around the plaza, trying to spot the gunmen and return fire. A posse member's horse is shot and killed. Then another. Then posse member Julian Lopez's arm is shattered when he takes a slug. Realizing the situation is hopeless for them, the posse retreats out of town and quickly ride back to Lincoln.
The Regulators dismount from their rooftop positions and hang around San Pat for a while longer, probably having breakfast and discussing their next plans. They no doubt know that more Dolan men will soon return to San Pat, with greater numbers. Deciding that the village is no longer safe for them, the Regulators, along with McSween, leave Patricio and head east down the Rio Hondo.
About four miles east of San Pat, the Regulators spot another posse quickly riding up behind them. This posse numbers about two dozen, is led by Deputies John Kinney and John Long, and contains Jimmy Dolan himself. The Regulators dismount their horses, grab their rifles, and take up positions along a ridge that keeps them out of the view of the Kinney posse. As the posse nears, the Regulators open fire. Two horses instantly are killed, and the posse turns and flees before anyone is injured or killed.
The Regulators, after they're certain that the Kinney posse is gone, remount their horses and continue riding east. Their plan is to head to the Chisum South Spring Ranch and take refuge there. Meanwhile, Kinney, Dolan, and Long and their men are furious over the fact that not only have the Regulators escaped them yet again, but that they did it twice in one day. The posse rides back towards San Patricio, intent on taking out their aggression there and making sure that the peaceful Hispanic community never harbors the Regulators again...
Regulators involved in both fights
Murphy-Dolan-Riley men involved in first fight
Murphy-Dolan-Riley men involved in second fight