A San Antonio-area doctor faces a capital murder charge after authorities say he killed two of his neighbors while they helped his mother Sunday morning.

Robert Edward Fadal II (Guadalupe County Sheriff's Office)

Robert Edward Fadal II, 56, of Seguin was booked into the Guadalupe County jail and remains in custody, with bail set at $2 million.

Anthony and Tiffany Strait had gone to the Fadal family's gated compound, a couple of blocks from their home, shortly before noon to help Fadal's mother move a piece of furniture, according to the Seguin Gazette. A sign posted at the gate wishes "peace, love, health and happiness" to everyone who passes through it.

Tiffany and Anthony Strait (via Facebook)

The Guadalupe County Sheriff's Office says that Fadal shot the Straits, who got married in May and owned a landscaping business, "for no apparent reason." Family members said the Straits' three young children saw the shooting from the backseat of their parents' car, according to KSAT-TV.

"There are no indications there was a feud, disturbance or anything precipitating or justifying the shooting," sheriff's Lt. Craig Jones said at a news conference.

Anthony Strait was pronounced dead at the scene; Tiffany Strait was taken to a hospital, where she died a short time later.

Fadal, a family physician, had his practice on the compound, Texas Medical Board records show.

A neighbor who reported hearing six shots, Rudy Soto, told KSAT that Fadal was "one of the nicest" people you could meet.

Authorities are investigating what led to the shooting.

"In cases like this, where we don't always understand the why of what goes on in our communities, it's a reminder that evil exists out there," Jones told KSAT.

A GoFundMe account has been set up to benefit the Straits' children, ages 7 to 10.